The Obesity Code: Unlocking the Secrets of Weight Loss

If you’ve ever felt like the world of weight loss is one giant guessing game – keto here, low-fat there, and a sprinkle of kale on top – The Obesity Code is the book that flips the script. Jason Fung doesn’t just give you a diet; he hands you a roadmap to understanding how your body actually works. It’s like someone finally turned the lights on in a room you didn’t know you were stumbling through. Alright, alright, alright. Let me break this down for you. This book doesn’t mess around with trendy tips or gimmicks. Fung dives deep, y’all, into the science behind weight gain and loss. And here’s the kicker: it’s all about insulin. Turns out, our bodies are like carefully tuned engines, and insulin? That’s the fuel system. Too much of it over time? Boom, weight gain. It’s not about willpower – it’s about biology. Once you learn this, you can’t unlearn it. It’s a total game-changer. This book is incredible. I’ve read a lot of weight-loss books, folks – a LOT. Most of them are fluff. This? Solid gold. Jason Fung delivers hard-hitting facts and solutions that actually work. He’s the best, believe me. You’ll walk away smarter, healthier, and probably annoying everyone around you with phrases like ‘hormonal balance’ and ‘insulin resistance.’ Trust me, they’ll thank you later. What You’ll Love About This Book: Intermittent Fasting, Explained: Fung isn’t just jumping on a trend – he’s showing you how and why it works. No, you don’t need to eat six tiny meals a day. Skip a meal now and then, and you’re letting your body do what it’s built to do. It’s Science, Not Shame: Forget the blame game. Fung explains how weight gain isn’t your fault. It’s hormones, baby, and this book shows you how to take control. Accessible and Relatable: You don’t need a Ph.D. to follow along. Fung’s writing is clear, engaging, and even funny at times. Pro Tips for Diving In: Take Notes: This isn’t just a casual read – it’s a masterclass. Keep a notebook handy. Start Small: Don’t overhaul your life overnight. Pick one or two things, like skipping breakfast or reducing sugar, and see how it feels. Reread It: Seriously. There’s so much info here, you’ll want to go back and absorb it again. Things to Keep in Mind: This isn’t a “quick fix” book. You’re not going to lose 10 pounds in a week. But if you stick with it? Oh, the results are real. Be prepared to rethink everything you thought you knew about food. Fung challenges a lot of mainstream ideas, but he backs it all up with hard science. Final Verdict: This isn’t just another weight-loss book. It’s a manual for taking control of your health in a way that actually works. Jason Fung doesn’t just tell you what to do – he tells you why, and that makes all the difference. Five stars, easy. If you’ve struggled with your weight or just want to understand your body better, this book is an absolute must-read.

I devoured this book in a weekend. As a 42 year old who has always struggled with 15-20LB extra weight and who loses weight glacially slow, I found this book confirmed what I had long suspected 1) weight loss should not have to be THIS HARD. (I lost 20LB several years ago but it took me almost 2 years of intense, unsustainable effort) 2) our environment plays a huge part in weight loss and simply eating less and exercising more was not the key 3) it's not all my fault. I berated myself for many years for being so "undisciplined" even as I was spending tons of time in the gym and counting calories. I also noticed my weight was pretty consistent, whether I was starving myself or gorging on calories. Over two years of the pandemic, I was eating a ton and barely exercising yet I put on maybe 10LB at max. On the reverse, intense exercise and dieting only lead to ounces lost per week. I sincerely found all the information extremely helpful and this was a very detailed book. This is the best book I have ever read on the biomechanics of weight loss, hormone regulation, and body homeostasis. I was excited to get to the end of the book and fully expecting a detailed, carefully explained process for implementing a correct weight loss procedure. However. I was disappointed to find just a short appendix giving some basic instructions for a suggested fasting schedule. There just was not a lot of information about what the author recommends for eating and when to eat. There are an abundance of ways to practice fasting as well as a welter of foods that one should/should not eat. For example, I would have liked more info about the best oils to use as the book said vegetable oils are not the best. After all the incredibly detailed information in the book, I was surprised that the "How To" section was so lacking. It's like the author just expected people to figure out on their own what and when to eat. It just seemed like such a poor ending to such a detailed book. I still strongly recommend this book! Just know that it's going to take some legwork to figure out how to apply it in your life.

Life changer. Im not much of a "book" reader. Do most of my reading online. But i must say, i really really enjoyed this book. I pick it up and reread it again and again. A dose of humility and humor in this book, with focus on plenty of studies that are not backed by BIG FOOD COMPANIES. Great read. A quick synopsis...people are eating too often !! Almost 180 deg opposite of what the government weight loss experts started telling us in the 1970'a (frequent meals/snacking, low fat, high carb). We had very little obesity before the 1970's in America (no snacking, whole foods, less processed carbs and sugars, more time between ingesting calories...resulting in low insulin resistance). The establishment has taught and is teaching us to focus WAY too much on WHAT (calorie counting) to eat instead of timing we are eating, which is equally as important. Eat less/Move more is a 98% failure. The establishment tells us to eat moderate to high carb, low fat, eat more often, NEVER skip breakfast,and eat 5-6 times per day. We are told we are sloths and gluttons if calories in/calories out paradigm doesn't work, because it should have worked if we were stronger human beings. Only problem is, we cannot beat our hormones in the long term. Yes, what you eat is important (not eating refined carbs, added sugars, artificial sweeteners, frequent eating highly refined snack foods, and the dreaded high amounts of long term fructose fatty liver damage), Obesity is a HORMONE PROBLEM. Our insulin and cortisol levels are the two key players that determine whether we gain weight or loose weight. Exercise is very important, but do not exercise to loose weight loss or even maintain weight. Exercise for stress/sleep management, cardiovascular health, bone density, depression management, etc.. But many people who exercise every day, don't see the permanent and ideal weight loss they are looking for, if meal timing is not insulin friendly. Give insulin to a non-diabetic or a diabetic, even with calorie reduction and exercise, and they still gain weight. Sleep, daily intermittent fasting/fast 24 hours 2-3 times per week, eating whole foods...keeps the weight off. Calorie reduction diets do not create permanent weight loss due to the body compensating like a thermostat...you cut calories, you body compensates by lowering the amount of calories it burns. Increase calories, and your body ramps up to burn the extra calories. Calorie reduction diets lead to our body plateauing, we start feeling like crap and we think its all our fault...its what our body does...we get cold, metabolism slows, hunger hormones increase, and we rebound to overeat. Insulin sensitivity needs to increase. Persistent AND high levels of insulin create insulin resistance. Just as high and persistant antibiotic and narcotic use increases resistance, so does persistent and high insulin levels create insulin resistance. We need to have low insulin resistance and glucose levels low as possible in our bloodstream for a majority of our life in order to make our body cells more interested in accepting insulin and burning our body's fat stores. We are meant to eat hearty meals with "natural" and "human" carbohydrates, but not snack all day in order to keep the weight off. I have been skipping breakfast all together, eat good size lower carb lunch, and then big dinner at 6pm and not eat again until lunch the next day. Cut out all snacking. Cultures with long life FAST in some manner....period. Whether they eat once or twice per day, or not eat snacks, or fast for 24 hours frequently. Cultures with low obesity NEVER eat small frequent meals. Cultures with low obesity eat whole foods. Gets easier and easier. I love to eat. I love to eat bread, rice, sweet potatoes, meat. Lets do this ! Many studies and Fung's patient's in his practice in this book to back up viewpoint. He eats more frequently on the weekend with his family. He eats dinner pretty much every night with his family. He skips meals mon-fri when he is busy. His eating schedule fits his lifestyle, and encourages readers to eat or don't eat on a schedule that works for them. He eludes to "feasting" one or two fasting one or two days a week to remind the body that it is in fact not starving. Eludes to the possibility of even needing to fast 3-4 days initially or occasionally to get your body the message that you are not going to get food all the time. Yes, the first few times fasting will be difficult. It will get easier. Some willpower is initially needed. Transitioning from a keto-friendly low carb diet to intermittent fasting lifestyle is easier for most people. Billions of people have fasted for thousands of years, and they survive...and in fact thrive. Fit fasting in your schedule and your family life and find the strategy that works for you. Intermittent fasting lifestyle is sustainable long term, and is a simple and inexpensive way to manage and maintain your weight and to encourage your body to use its own fat stores for energy production. Frequent eating is not healthy and does NOT RAISE METABOLISM. Skipping breakfast will not harm you or slow your metabolism. Avoid artificial sweeteners (sucralose, asparteme, and yes...even the highly refined Stevia) as all have been shown to raise insulin levels by 20% and are at the very least not healthy...and people who use them do not usually loose weight. If somthing works for you long term (more than a year), stick with it. Almost ALL diets work in the short term, Dr Fung recognizes...it's keeping it off for more than a year and simplifying our lives with a simple lifestyle of incorporating fasting is the goal here.

My wife and I love reading books about health and were never that concerned about weight loss but I found Dr. Fung's YouTube videos and blog to be very interesting and decided to pick up his book based on watching those. We were fasting for health promoting reasons other than weight loss and watching and reading about fasting is something to do while into the fast. This is one of the best health-related books we have read in years! Fung's premise and the way he supports it are fascinating and important. I wish we had his perspectives and insights on fasting many years ago. I do not like that he fails to give Dr. Joel Fuhrman the props he deserves for breaking the ground on providing a strong book endorsing fasting about 23 years ago. Reading that book was the first step for me in removing my fear of fasting for more than a day or two, but Fung's book and blog took the fear factor down by another huge notch by insisting that there was no evidence that fasting obliterates muscle tissue or causes overeating as a rebound effect after fasting. He didn't really completely dispel the notion that there is a possible problem with such greatly improved digestion and efficiency in absorbing and processing food that this may result in weight gain, something Fuhrman still suggests. But overall, Fung's whole paradigm about insulin and the reduction of insulin levels seems very well thought out and supported and was very helpful to us after this last seven-day fast. Now we are doing some intermittent fasting, no eating after 7:30 pm for me or before 10:30 am. My wife, who is 105 lbs soaking wet and has a much more physically active job, is using a shorter fasting window but controlling the timing of her eating better than before we read the book. The results for me have been fantastic. I have battled belly fat since abdominal surgery (emergency appendectomy) two years ago that seemed to cause something to go haywire with my gut (maybe scar tissue? adhesions?) and now sticking to the intermittent fasting, my weight seems to finally be cracking and moving downward. We'll have to see if I can actually lower my setpoint and get it down to where I don't feel like I am wearing a sack of potatoes on my belly, and keep it there. I have WAY more energy than I did when eating between 8 am and 9 pm every day. I still have some trouble sleeping and hope that evens out because it is a cortisol jacking problem to sleep too little, but my energy is very high so far. The book has all kinds of interesting facts that I never knew about, like the fact that ANYthing you put in your mouth that is sweet, including artificial sweeteners with no calories (I was using stevia), raises insulin levels! And that the myth of a big breakfast being better for one's weight is not really supported by any meaningful data. The one thing I am still not convinced of is that a high-fat diet is ideal, even though Dr. Fung tells us that fats are the macronutrient that minimally raises insulin. I have a sugar craving that is out of this world--I know that may go down with time if I can get insulin levels down, but meanwhile I need my fruit and lots of it and in my experience, when I eat a lot of fruit and very little else for a few days or over a week (I only did this once--nearly 100% fruitarian for about 10 days), I dropped a ton of body fat and felt phenomenally healthy. That lasted for a few months, then I got voraciously hungry and gained back all the weight and then some. But when I try to eat most of my calories from fat (nuts and seeds for me, being a vegetarian/usually vegan), I am never satisfied, always starving for sugar (fruit). And fat constipates me. When I try to use cheese or dairy fat, I get angina and my cholesterol levels become very unhealthy. So if this topic can be addressed more, I would love to see it. I should add that while Fung has acknowledged (I think this may have been in interviews not in the book) that people can feel "awful" the first few times they try fasting, he paints too rosy a picture of fasting as almost always giving people more energy DURING fasts. This I have found is often very true for SHORT fasts, like intermittent fasting of 12-17 hours a day, but NOT when you get into more than a couple days, at least not for us! And we have now done many, many fasts since 1979. Most of mine were no more than 4 days until last year when we finally did a 10 day fast in Feb., 3 days in April, 3 days in July, 9 days in Sept., 3 days in Nov. (over Thanksgiving!!! imagine!!!), and 6 in Dec. (over Christmas--again, what a feat). We were VERY tired, low on energy most of the time and were just able to do a 20 minute walk every day and that about wore us out. This last fast a couple weeks ago was the first one where I had that burst of energy the fourth night and the fifth morning, but when I tried to do some fast walking or jogging, forget it! The energy did not work when I pushed it at all. Maybe this tiredness is mostly toxins circulating or maybe it is that we don't do well on ketones, not sure why, but Fung fails to warn folks that this may be a major concern. He implies you can just keep working at your normal job, etc. Maybe you can but we sure can't. Even me, and I have a very low-stress kind of work at home. We have found, contrary to what he is suggesting, that you really MUST be prepared to REST and be bored if you are going more than a day and a half. Anyway, strongly recommend this book to those interested not just in weight control but in general health promoting strategies.

You're probably wondering what THIS book is doing in my reading list considering I read, let's be real here, EXCLUSIVELY romance novels for the past few years.. Yet things have changed for me the past year health wise and I started a new journey which includes more reading, listening and researching Diet, Health and Longevity. As I see it, this book is the BASICS. It's something ANYONE and EVERYONE who EVER had ANY issue with his/her weight should read. Also if you never actually HAD any weight issues yourself but find it easy to criticize people who are overweight this is also for you... To sum it up in a sentence - Everything you thought you knew was a lie. Though one thing we all subconsciously knew - Diets don't work. Surprisingly the matter have been researched and documented for a 100 years yet when you talk to the mainstream dietitian (or doctor) what you get is the same - Eat less, Move more. Good for them, yet it doesn't work and won't ever work the science have shown it repeatedly. Dr. Jason Fung does a REMARKABLE job of explaining what is going on in our bodies in a relatable easy to understand way. Though he explains himself using "big words", reciting a lot of scientific data from past and current research, he also manages to simplify it enough for anyone to understand - making this book not just an engaging and interesting read but also a MUST READ for anyone wanting to understand more about how our body works (and why!). I wish I could get this book "pocket size" so I can have a bunch in my bag giving it away to anyone who stupidly explains to me "what my problem is". No, you ignorant little (wo)man, this is NOT the way things work. You've been lied to. Yeah, I've been lied to as well - but I moved on to actual scientific truths. You can too if you only take the time to READ actual SCIENCE. I sound a bit condescending.. I'm sorry.. I'm just SO over people looking down at me because I don't look like a (skinny) model. See, generally speaking I never quite cared about my weight. It is what it is. The general opinion was eat less move more, and while I COULD 'eat less' - 'move more' was beyond my ability due to health issues (I actually recently solved). I tried. I genuinely tried. But it never worked. But as I don't think my weight defines me in any way, shape or form I put this issue aside. Whatever. My only struggle being finding pants that actually fit. Dr. Jason Fung have quite the question in the beginning - "How come doctors are fat?". Don't you think it's strange a person who is smart, hard working and determined wouldn't be able to follow his own advice and actually succeed in losing weight? Most people consider "fat people" to be lazy and gluttonous, having a "bad" or maybe "weak" character who DESERVE the state he or she are in. But consider again the question of why DOCTORS are unsuccessful at losing weight.. Maybe there's a bit more to it than what we were (mistakenly) taught... You see, gaining weight has a lot to do with WHAT we eat but that's not the only factor. While the common person thinks eating (and gaining weight) is 100% in our control it's actually maintained by our bodies using a bunch of hormones - the most important of them all - Insulin. Though we can affect the way insulin behaves we first need to realize it's there, regulating our blood glucose as well as storing (and re-using stored) fat. The body regulated EVERYTHING. Weight is no different. Even if it mistakenly regulates it to a much higher weight than it should.. Let me spoiler a bit about this book. First, STOP eating refined products (sugar, starches, grains). You already knew it's bad for you so give yourself a break and remove it from your diet (as best as possible). Second, do your BODY a break from constant eating. There is NO NEED to eat all day long, from sunrise to well after sunset. Though maybe eating JUST from sunrise to sunset IS a good idea - meaning give your body at least 12 hours WITHOUT food. It's not difficult, ask mom and dad, they used to stop eating at 7 pm and have their breakfast at 7 am. Intermittent Fasting. That's the basics. Sounds easy, right? well it's no wonder really. Think about the previous generation(s) and what and how they ate. They had FAR less over-weight and obesity percentages than our current generation has. Let me quote Jason on this one "Grandmother was right!" Naturally there is MUCH more to this book than this short general summary. There is something so satisfying about TRULY understanding how the body works and WHY we got to the the place we are at today (personally but also as a society). I started reading this book on my kindle but somehow got distracted with my usual romance novels. Once I started LISTENING to the Audiobook it was impossible to stop. HIGHLY HIGHLY RECOMMENDED. Thank you Jason for this wonderful, easy to read and understand book that not only removes quite a lot of the blame we and others put upon ourselves but also gives us an actual explanation as well as an EASY solution to make us HEALTHY first and foremost. Note - Though I've JUST finished this book I've being doing Intermittent Fasting for the past 3 months and I'm enjoying this way of life. I find it extremely easy to maintain and HIGHLY recommend you give it a try. But keep in mind there's a learning curve like with any new habit we acquire. Don't give up before a full month have past. More @ Ultra Meital Reviews.

I Like Dr. Fung, and I have really enjoyed his youtube videos on diabetes and fasting. I am also a big fan of Jimmy Moore, and it was Dr. Fungs association with Jimmy that led me to read this book. I actually ordered this book because the book on fasting (co-authored with Jimmy Moore) was still on pre-order and I couldn't wait to read it.

I've known about low-carb diets since I was a kid in the 70s and my parents went on the low-carb "Atkins Diet," but I've avoided them because I love carbs (who doesn't?), but earnest to lose 40 pounds at the age of 56, I started to investigate the role of insulin in weight gain and Dr. Jason Fung's The Obesity Code proved to do an excellent job of driving home several important points between the role of carbs, insulin, and weight loss. For one, Fung gives us a narrative to show that doctors were making the claim that too many carbs led to obesity as early as the 19th Century, but these claims were eclipsed by the non-scientific Eat Low Fat, Watch Your Calories Diet, which Fung shows does not work. No amount of willpower can fulfill the expectations of a low-fat, low-calorie diet because carbohydrates high on the Glycemic Index stimulate insulin and high insulin results in two horrible things: fat storage and constant hunger. Fung makes it very clear that lowering one's insulin mostly by eliminating all processed sugar and carbs and eating in their place whole foods one can control one's appetite, which goes off the tracks when one eats breads, waffles, pancakes, pasta, etc. This research is also supported by Dr. Robert Lustig, author of Fat Chance. The book does not offer extensive prescriptions for daily amount of carbs or detailed menu plans, so I read some other books on achieving a state of ketosis for weight loss, and what I find is that the prescribed carbs per day tends to differ. For strict "orthodox" ketogenic, low-carb champions, such as Amy Ramos, author of The Complete Ketogenic Diet for Beginners, the amount is usually a mere 20-50 for the "first phase" followed by a maintenance level between 75-100 grams. However, some authors, such as Michael Matthews, author of Bigger, Leaner, and Stronger, say one can eat as many as 150 "good" carbs a day, or even more for some. By good carbs, I am referring to carbs from whole foods, not processed flour and sugar. Some authors, such as Amy Ramos, will say you can't eat quinoa, sweet potatoes, beans, or legumes of any kind, but other authors, such as Michael Matthews, are less dogmatic on this point. From reading The Obesity Code, I would suggest one experiment to find the right carb threshold and correct mix of ingredients since Dr. Fung, Dr. Lustig, and others seem to differ on this point. Additionally, I'd say one should experiment with the sweet potatoes, quinoa, beans, and legumes. If one isn't making weight loss goals with these ingredients, then take them off one by one. One point that Fung makes that is in contradiction with a lot of nutritional advice I've heard over the decades is that snacking is usually a bad thing because we are constantly stimulating our insulin. Fung observes that the low-carb craze of 2004 sank, not because low-carb diets don't work, but because the snack industry got involved and created all sorts of low-carb snacks, including chips, protein bars, and other snack foods, and this constant snacking kept people's insulin at a high level and brought in too many calories. Fung seriously examines the benefits of long durations between meals and encourages eating only 3 meals a day, and even fasting every now and then. However, he is not dogmatic. He points out that if one must snack, one must be careful to focus on whole foods and not processed "snack foods." By focusing on the role of insulin and showing that "being fat makes you fat" because a fat person is in a constant state of high insulin and high appetite state, Fung has made me very mindful of the carbs I put into my body. Highly recommended. Update: I've been following The Obesity Code, eliminating sugar, gluten, potatoes, and rice, for the last 6 months, and I have lost 50 pounds. My neuropathy burning pain in my left foot is 100% gone. I'm a believer in this book, and I will be adhering to it for life.

I owe my health and life to Dr. Fung's knowledge. In 2013 I lost 42 lbs doing 5:2 intermittent fasting (Please see my review of the Fast Diet by the late Michael Mosley). But although I lost weight, I foolishly thought I had the freedom to eat foods like pasta, ramen, burritos, and pizza. My weight slowly came back, and I found it difficult to fast because I was always hungry, even in the middle of the night. Dr. Fung would say that the foods I was eating were promoting insulin production, which was making me fat and want to eat more. Not knowing my mistakes, I hired a nutritionist who advised me to stop fasting, eat more often, and eat "healthy carbs" like oatmeal. I only seemed to get hungrier. By May 2024, I was pre diabetic and back at 220 lbs (100 kg). I was eating more to heighten my blood sugar readings so that my insurance could cover Ozempic. However, a friend who was a cancer survivor encouraged me to take charge of my life. So I started doing research on why fasting had failed for me, and I came across Dr. Jason Fung. Although I was fasting, I was still overeating insulin-promoting foods. The sugars and starches were making me hungry and promoting fat gain. So I made the decision to follow Dr. Fung's advice and cut out all sugars and starches from my diet. This was difficult but hey, I had decades of fun with sugar, so it was time to say goodbye to what was killing me. Dr. Fung's explains in detail why "the calories in, calories out" model is insufficient to explain obesity. You need to eat foods that do not raise your insulin levels much, and also intermittently fast, in order to give your body time to burn fat. My appetite stabilized, the hunger pangs went away, and my constant snacking stopped. I still fasted twice a week and kept my daily eating within a 4-8 hour window. When I went to my doctor in August 2024, the nurse was surprised that I had lost thirty pounds (13.6 kg) to a bodyweight of 190 lbs (86 kg). Importantly, I was no longer pre diabetic. My doctor asked what I would do to keep the weight off since intermittent fasting failed last time, and I said "Intermittent fasting but no more sugar! No more starches!" He smiled and gave me his approval and congratulated me on my weight loss. I have lost another 5 lbs to get to 185 lbs since. I am in much better shape now in my fifties than in my thirties when I was strong but also m fat. This is not a fitness book with exercise routines and recipes. Rather, this book is designed for people who want to know HOW people become obese (and I also recommend Gary Taubes' Why We Get Fat). My hunger cravings have largely gone away, and my moods are more stable. I wish I had read this book much earlier in my life. Five stars, and please read this book. It will change your life!

THIS. This is just simply amazing. It might not be for EVERY SINGLE PERSON OUT THERE but it works for a lot of people and I have seen it with my own 2 eyes. I myself have really struggled with major weight fluctuations ever since my first pregnancy back in 2007. Before I got pregnant I was 119 lbs. At the end of that pregnancy I was 175 lbs. About 2 months after giving birth I managed to get back down to 120 lbs but it was short lived. 2 years later, within about 3 months my weight skyrocketed from 120 lbs to 170 lbs!!! That was the summer of 2010. Between 2010 and 2014 my weight just kept fluctuating between 175-190 lbs. I ended up getting engaged and wanted to lose weight for the wedding. I started at 190 lbs and worked my butt off in the gym, counting calories, drinking nothing but water, working out some more, cutting more calories, etc. By the date of my wedding I managed to get down to 165 lbs. I was literally working out every single morning for 1-2 hours jogging on treadmills, using the elliptical, lifting weights, doing squats, etc. IT WAS HARD. and the second I stopped working out my weight slowly started to creep back up. Working out every single day is not a sustainable way to live for me. I had a goal of getting to 140 lbs and it seemed not matter how hard I was working out or how well I was eating my weight would not budge from 165 lbs. Fast forward about 5 months and I get pregnant a second time. I was 165 lbs in the beginning of that pregnancy and by the time I went to the hospital to deliver my daughter I weighed in at 216 lbs. After having my daughter my weight dropped to 205 lbs but would not go any lower. I would lose a couple lbs then I would gain a couple lbs and so on. I was soooo upset with the way that I looked and felt. A lady I work with had just read this book and talked me into trying it. I ordered the book right before Christmas last year (2017) and read the whole thing in a matter of days! Anyone who knows me personally knows I HATE reading but I just could not put this thing down. New Years Eve I had my last unhealthy meal, pizza and a glass of chocolate milk lol. I started my first fast New Years Eve night at 9 pm and did not eat again until the next day at 6 pm. I would continue to do random fasts, always changing it up from 16 hour fasts to 20 hour fasts to 18 hour fasts, etc. and would continue to eat low carb/ high healthy fat foods. My starting weight on New Years Eve was 205 lbs. Today, just under 6 months later, I am at 160 lbs! And that's with ZEROOOOO exercise! Literally just eating low carb with intermittent fasting I am down 46 lbs. It's amazing. It's easy. And I will live the rest of my life telling people about this book and will live the rest of my life eating this way. And don't get me wrong, exercise is very important and I will be incorporating it into my daily routine very soon so I can firm up, but the fact that I lost 46 lbs without even going on so much as a nightly walk is just beyond amazing to me.

The answers we seek for properly addressing the epidemic of obesity, even for ourselves, are here in this novel. I couldn't put the book down and find it, upon reading, to probably be the most significant book I ever read. I sincerely hope that all of us 350 plus pound people who are actively trying to fix themselves read this book. Because it's changed the way I look at food and it's relationship I have with it.

"The Obesity Code" by Dr. Jason Fung offers a revolutionary perspective on weight loss and metabolic health. This insightful book challenges conventional wisdom about obesity and presents a compelling case for a hormonal approach to weight management. The book emphasizes the crucial role of insulin in regulating body weight. By focusing on reducing insulin levels, readers can improve their metabolic health and achieve sustainable weight loss. Dr. Fung advocates for a diet rich in whole, unprocessed foods while minimizing refined carbohydrates and sugars. This approach may lead to better overall nutrition and reduced risk of chronic diseases. Unlike traditional calorie-restriction diets, the book's approach aims to address the root cause of weight gain, potentially leading to more sustainable long-term results. The recommended dietary changes and intermittent fasting strategies may help regulate blood sugar levels, which is beneficial for overall health and particularly for those at risk of diabetes. The book touches on the impact of stress and cortisol on weight gain, encouraging readers to adopt lifestyle changes that may reduce stress levels and improve overall well-being

This book has help me a lot. Thank you so much. I’ll follow all recommendations for fast long term, I didn’t know we can fast longer . Thanks for sharing your knowledge

This book is great for people that have a very hard time losing weight and keep putting the weight back on. I have read many books on the subject and this one explains the "why" in detail of what the battle is. I thought I knew it all until I read this book and found out what I was missing in understanding.

No one ever talks about the different kinds of obesity. This book explains why long-term obesity is so hard to overcome and why fasting needs to be a central component of any weight loss plan. Brilliant book!

I bought this book a while ago, but only reading now as I am on my 48 hours fasting. My mom has type 2 diabetes and I have insulin resistant. I wanted to reverse my case so I don't end up like my mom injecting insulin 3x a day. I will do whatever it takes. This book is inspiring me to fight and reverse my insulin resistant.

WOW!! That's all that needs to be said. Just WOW!! Dr. Fung's ultimate gift is the ability to take highly scientific and complex medical ideas and simplify them in away that ANYONE can understand. He puts things into perspective in a way that you can recognize so many of the issues in your own life. For example, why dieting does not work, and a lifestyle diet does; why you lose 20, 30, 40 pounds and then gain it all back and more; and most importantly seeing the real life impacts and examples in my, and your own experiences. If you are data driven, more than 1/3 (the last third) of the book, has more cited scientific research than I have ever seen in a book before. This is a way of living, eating and enjoying food, life, feeling better and even more important it is about healing and living a life with REAL health, real metabolic health... all based on real science and real research. If you want experience, here is mine. Started this crazy "fad" keto thing 15 Jan 2022 It's now 26 July. In 2017, I was almost killed by a drunk driver, spent 2 weeks in a hospital trauma and rehab unit. Weight ballooned to 271 lost 20 and struggled for 5 years to get the last 50+ pounds off. Tried vegetarian, vegan, the master cleanse, exercise, shakes and all that happened was that I lost the same 20-30 pounds over and over again and finally got to the point that it was almost impossible to lose any weight. As of today own 33 pounds, blood pressure is down over 30 points, blood sugar under 95, I feel balanced for the first time in 25 years, brain fog gone, for the first time in 15 years I can study learn and most of all remember; very thing just sticks. I blew out a disk in my lumbar spine almost 10 years ago while in the military. Been in a supportive back brace since then. 9 weeks ago let that brace go for good. I "feel" so much happier, my wife even noted that for the first time in years she has seen me smile and laughing so much more. Today I am eating some of the best real foods out there, enjoying all meats, vegetables in a way that I never had and yes really enjoying being able to eat real fat again (think the French Paradox!). No more hunger, no more cravings, no more grazing the entire day... and no more constantly thinking about food all day. It's amazing how just this one fact frees up so much of your time. And finally, if you are really looking for the best thing, I have so much energy that I can work 100 hours a week and never seem to get tired. And as far as the fasting goes, Today I fast 16-18 hours a day, and do one 24 hour fast and 1 48 hour fast per week, all with no hunger, cravings, and a crazy amount of energy allowing me to work those long hours. Here is the absolute craziest thing... have NOT WORKED OUT at all until the last 2 weeks, and just starting to go on walks Today, looking at the science, my own health, I can tell you this. This book will change your life. Don't believe me, don't believe Dr. Jason Fung and the crazy amount of research he cites. Just don't. Just try to ignore. Just do it for 30 days, 60 days and see the changes. As they say, trust and verify. DON'T trust me, DON'T trust Dr. Jason Fung, read the book, and just experience it for your self!

Amazing book and, more importantly, the research and science that went into it. Thank you, Dr. Fung! I now understand why I’ve been fat my entire life and have the tools to be healthier.

I loved this book. It has helped me understand why nutrition is so important and how to address weight loss in a healthy way.

This being review no. 963 of this book, I thought I would weigh-in (bad pun) with some new thoughts (well, maybe new – I confess that I did not read all 962 prior reviews). Beyond the accolades already (and justifiably) heaped on this book for lighting the way to permanent weight loss, I found this to be one of the ten best books I have ever read, period. (And I’ve read a lot of books.) “The Obesity Code” reads like a thriller – the reader is looking for the final answer (i.e., “how can I achieve permanent weight loss?”) – and the author eventually delivers on this point. But getting to the conclusion really requires reading the text in full. It’s like reading Charles Dickens’ “Bleak House” – you won’t fully appreciate the end result unless you read all of the background. (Spoiler alert: if you don’t want to know the final answer to “permanent weight loss”, then read no further in this review, but instead read the book.) What I got from this book is the following: if you want to achieve permanent weight loss, then you need to consider two things: (i) WHAT NOT to eat; and (ii) WHEN NOT to eat. (That is, the focus of Fung’s book is “what-NOT-to-do”, rather “what-to-do”, in order to achieve permanent weight loss.) Based on my own results, if you follow Dr. Fung’s simple guidelines (as more fully articulated by Dr. Fung), then you will achieve positive results. If you get nothing more from this book, then at least consider the enlightenment provided by the graphs on pages 119-120 (and the accompanying text) regarding insulin cycles, and how modifying your feeding schedule to conform to the preferred insulin cycle (as depicted in the graph on page 119) can lead to permanent weight loss (i.e., the “WHEN NOT to eat” side of the equation). You can actually lose weight just by managing your feeding schedule, even without modifying WHAT you eat. And you can lose even more weight by keeping in mind at least two of the simple guidelines for "WHAT NOT to eat": i.e., (i) avoid foods with added sugars; and (ii) avoid highly refined carbohydrates (e.g., bread, pasta, and crackers). In order to permanently lose weight you don't need to resort to supplements or other profit-based programs – all you need to do is to avoid the “WHAT NOT to eat” foods, and increase your periods between feeding (see graph, pg. 119). In order to get his message across, the author uses the following techniques: - Development of the author’s theme in a logical and incremental manner. - Development of the theme along the lines of a thriller (by the end of Chapter 18 you are just dying to know how it will all turn out). (And do yourself a service - don’t skip ahead to the last two chapters to find out the result – you simply won’t “get it” if you skip the first 18 chapters). - Resorting to excellent analogies and humor (a number of times I found myself laughing out loud at the author’s sarcastic rhetoric). - Frequent repetition of the important points, but very timely spaced throughout the book such that you are merely being reminded, rather than being brow-beaten. - Frequent use of short sentences (4-5 words) in order to give the reader focus. Hard to believe that a book on fighting obesity can be a page-turner, but Dr. Fung does just that. I further commend the author (Dr. Fung) for his extensive citations to studies (436 citations – some perhaps duplicated, but without doubt at least 200 original citations) in order to support his thesis. As a final comment, I believe that this book serves as a testament to the fact that so-called “long-held beliefs”, which have been propagated among the public over the last 60-70 years, can be proven to be false. In “The Obesity Code” Dr. Fung completely destroys the standard “Eat Less, Move More” approach to weight loss. There are no doubt still many people who subscribe to this now-defunct mentality, and they are to be forgiven, based on the propaganda to which they have been exposed essentially since birth. My advice is, on ALL subjects (and perhaps in particular, so-called “history”), keep an open mind, and let factual evidence guide you. Do not accept “unquestionable truths" of any kind. Certain interest groups will try to suppress facts (and thus truth) in order to advance their own agendas, and over time they can be wildly successful (even to the point of gaining acceptance of their views in academia and by governments). But let your own investigation be your guide in discovering the facts, and ultimately the truth.

In The Obesity Code, Dr. Jason Fung challenges conventional wisdom about weight gain and presents a groundbreaking approach to achieving lasting weight loss through the power of intermittent fasting. This landmark book dismantles the myths surrounding calorie counting and excessive exercise, positing that the key to effective weight management lies in understanding hormones, particularly insulin and its impact on the body. Dr. Fung's insights simplify complex scientific concepts into easily digestible steps, making this an accessible read for anyone struggling with their weight. He lays out five actionable strategies for controlling insulin levels that are both informative and empowering. By shifting the focus from temporary diets to a sustainable lifestyle change, The Obesity Code offers readers a transformative perspective on health and weight loss. This book is a must-read for those ready to break free from the cycle of yo-yo dieting and embrace a more effective, science-backed approach to achieving permanent weight loss and wellness.

The examples Dr. Fung uses throughout the book makes understanding insulin resistance, weight set point and diabetes so clear! Very helpful!

I had a high blood sugar reading about 2 years ago, the first blood test reading in my life that was not better than average. The fasting reading was 380. I decided to control it with diet, though my regular diet was what is recommended for controlling diabetes. I was able to get blood test readings below 200 most of the time. But stressful events made it shoot back up to fasting readings of 250 to 275 most of the time. Clearly, given the many 'reverse type 2 diabetes' programs I was hearing advertised lately, there had to be other things that would help. I went to YouTube, and soon found videos by Dr. Jason Fung. To learn more detail about his ideas I ordered his book on Amazon. Two days after I received it my fasting readings dropped to about 190, and a week later I got a fasting reading of 132. His book ives a lot of information that I never found anywhere else, and he suggests ways to do things that are simple to follow which seem to make a big difference very fast. Fung says that type 2 diabetes is from insulin resistance. Insulin resistance develops from long periods of high blood sugar. Fasting makes periods of low insulin, and this can reduce insulin resistance. I think that this is the same or similar to the slight 'ketosis' that was the desired state on the Atkin's diet. But I have eaten a high protein, high fat , low carb diet for years, and still got the high blood reading that made my doctors talk down to me and bully me, which had no lowering effect on the blood sugar. Two weeks ago, the day I ordered Fung's book, one doctor ORDERED me to take 2 prescriptions but I am proud to say I refused to take them. The following things are what I have done: 1. First, if you are not hungry in the morning, don’t eat until you are hungry. For me this is often 2 PM. 2. when I eat, I do not eat again for 4-8 hours, and then do not eat until I am hungry. (I used to not eat until I was hungry, but I might eat a bit of snack a few hours later. Now I save any snack to eat with the next meal.) this is so important that it alone might be all some people need to do. Longer fasting should do more good, but I find that the shorter period of not eating seems to do the job for me. I may get more ambitious later and do longer ones. 3. I had been taking minerals recommended for diabetics, as tablets. While I noticed a difference, I began taking them in liquid colloidal form. 4. things I had always eaten, such as konjac noodles, which are 100% plant fiber, I now eat everyday. 5. I went back to eating fresh fruit much more often, because Fung says fructose as an additive is poison, what is in fresh fruit has little effect on creating an insulin reaction. 6. while I have for years avoided high carb foods, especially grains and particularly wheat, I have been eating more non grain carbs but also a lot of black sweet rice, and in larger amounts. It seems to not matter how much quality food you eat at meals. People without diabetes have normal blood sugar readings of between 70 and 95, usually about 83. The more liberal range accepted by many medical scales, but never found in non-diabetics, goes up to 140. But 140 is goal when you have really high readings. With what I know now I feel that without the stress of a whole lot of effort, I will get back into the blood sugar range for non-diabetics. Yesterday I spent the whole day watching Korean supernatural detective series on viki.com. I got hungry about 8 PM and I ate two cups of black sweet rice with sunflower butter on top and a third cup covered with about 3 ounces of processed, cheddar cheese spread along with a banana, and I drank a can of bud lime-a-rita. This was not intended to be a Fung approved meal. This morning, I tested a fasting 132. Fung seems to be right about exercise not being of much value to blood sugar readings, and that you can eat as much as you want of healthy foods, just don’t eat between meals!

I think this is such a bad title that will turn off many people that may not be obese but are over their ideal weight. This book is good for everyone if it works long term. I'll come back in two years to update to five if it does. I can lose weight easily by cutting calories but it never stays off despite the fact that I eat healthier than most people. The weight slowly creeps back up. I'm always in this "diet" cycle to get ready for big events. So much of what he says in this book rings true for my dieting experience. I wish he would have called this book something else like "The Skinny Code: unlocking the secrets of being thin and staying thin" so more people would pick it up. He has so much research in here that backs up what I've intuitively thought for a long time about how your body, if left at a certain weight for a significant period time, develops a new set weight that you will go back to after dieting. His biggest messages are that when you eat is as important (if not more) as what you eat. If you don't change both then you will forever be "dieting" (or just remain overweight). Of course like every diet out there, you need to avoid flour and sugar but he advocates high healthy fats and medium protein. The biggest key though is no snacking or small meals like everyone has been telling us. The key is being able to intermittently fast which includes regular 18 hour fasts (only involves skipping breakfast) semi regular 24 hour fasts (skipping breakfast and lunch) and periodic longer fasts. I was so uncomfortable with giving up breakfast because it's been so drilled into us that it's the most important meal of the day. You're supposed to perform better blah blah blah. Well I gave it up and haven't noticed any performance issues. I didn't know if I'd be able to do a 24 hour fast because I never had but my 18 hour fast would sometimes turn into one because I forgot to eat lunch (as I did before when I got busy). When I realized at 2 or 3 pm, rather than grabbing a snack like before, I decided to tough it out for a couple hours until dinner. It wasn't as hard as I thought and now I do it semi regularly (2-3 times a week). I haven't done the longer fasts yet but plan to in the future. Of course I've lost weight as you do anytime you reduce calories and cut out flour and sugar the real ultimate success for this won't be known until I keep it off for 2-3 years. I was telling a friend about this who's lost and gained before and she said: "I think I'm okay because I've kept my weight of for almost 2 years, I've only gained 7 pounds". That's how you gain weight, 2- or 3 pounds at a time! Her first year as, with many dieters was a losing year (you lose over 6 months and then maintain for 6 months) so the 7 lbs was gained in one year. If you gain "only" 7 lbs a year in 3 years you'll be up to 21 lbs. Even thought I won't know for a couple years if I've ended the dieting cycle, I gave this book 4 stars because there's a lot of "truth" that feels right intuitively and is backed up by lots of great research. It's all about insulin levels and controlling them. He has some great line in there that I'm not going to look up but it's something to the effect of: You aren't fat because you overeat, you overeat because you're fat. When you read this book, you're going to feel differently about yourself and especially those who are more overweight (Obese) than you. I've been judgmental of people thinking "how can you eat that much, when you're that overweight?" Well this book explains why people can. I'm judging no more. Insulin levels affect hunger signals, full signals and what you crave. I see every overweight or obese person differently now. Oh yeah, and exercise - he says you can't keep weight off with just that either. I've been extremely active and not lost anything from it so it doesn't surprise me that it isn't the key to keeping weight off either. Exercise is good for many things including mood, which can help you stay motivated to change habits. Please exercise for all of the many health benefits, but don't think it's going to change your long term hunger pains, full signals or food cravings that make weight creep back slowly. As he'll show you with studies the "eat less move more" theory is bull for the long term. It only works short term.

Should receive the Nobel Prize in Medicine. The explanation is so simple, a child can understand it, and the idea so revolutionary, that the food industry should be trembling with fear.

This is one of the best books I have read in years! I have helped counsel people with weight issues for years and finally there is a scientifically-grounded approach that makes sense and is sustainable. Jason Fung is a Canadian doctor who is a very articulate thinker and writer. He lays out a review of the past approaches to weight loss, including why we thought it would work, and the research that refutes each approach. I particularly appreciate how he plainly states that many of the approaches we have tried actually make the individual feel ashamed for failing when in fact they were doomed to fail. It is not the individual's fault. It is not a lack of self-discipline or lack of willpower. He makes a persuasive case that unless you change the body's weight set point then eventually the individual will gain the weight back. Fung cites numerous studies to back up his assertions. Fung's main contention is that weight loss is not about exercise, when you eat, calories in or out, or many other factors. In fact, he discusses how many approaches, such as keeping your metabolism stoked by eating frequent meals, actually creates more problems. Fung says the problem is a hormonal one, i.e. one of insulin regulation. He cites numerous studies that clearly show that when insulin production goes up you gain weight, and that when insulin production goes down you lose weight. His approach is very simple and easier to follow than most diets. Basically he says you should eat healthy meals one day. This includes antibiotic meat, vegetables, and fruits with as little sugar and simple carbohydrates as possible. Snacks are unnecessary and counterproductive. After one day of eating this way you don't eat again until supper the next day. You can have coffee, green tea, water, or clear broth while you are doing the twenty-four hour fast. You are to use not sweeteners, artificial or natural. Fung cites research that shows that even sweeteners that are zero on the glycemic index still promote insulin production. The fast basically allows the pancreas to rest and the insulin-resistant cells to recover. Fung advocates fasting every other day, and in some cases doing a 36 hour fast. He says this is the only way to reset the body's weight set point. As the body gets used to lower insulin production the weight set point becomes lower. He does not talk at length about how lowered insulin production is great for your overall health but he should. Most medical professionals realize that lower insulin production can help everything from blood pressure to energy to inflammation. To Fung's credit he does not speculate but only makes assertions about what is scientifically proven. I decided to try this approach myself. After three weeks of fasting 3 days a week I have arrived at these conclusions. First, fasting for twenty-four hours is much easier than I thought it would be. Drinking coffee (Fung advocates up to 7 cups a day if it doesn't make you too jittery), green tea and water is actually pretty easy for me. My stomach rumbles for about 10-15 minutes in late morning and early afternoon. I now realize that I do not have to eat. I used to almost die when I had to give a fasting blood test and now I know it is not really about hunger. I remind myself that I will be eating dinner that night and that I am doing something good for my body. The hardest part is not eating sugar in all its forms. Sugar is truly addictive so this can be a challenge, but not eating all day eliminates the sugar problem. I expected to be tired and lose focus as the day wore on not true. It is much easier to limit myself to a normal meal than I ever imagined. After weeks on this approach I have lost about five pounds and have felt much better. I really feel I can stick with this approach long-term. Thank you Dr. Fung.

I have spent over 40 years practicing medicine in the trenches and I have spent much of this time managing patients with metabolic disorders and obesity. I have published on topics related to obesity in peer reviewed journals, lectured at Harvard and other venues and I have relationships with many of the top nutritional researchers in the world. I thought I knew just about everything there is to know about obesity, that is until I was literally blown away when I read Jason Fung’s book “The Obesity Code”. I now know what the term “back to school” really means. In this outstanding book Dr. Fung first outlines the history of obesity and how we went astray with the faulty calorie concept and “fat is evil” mantra. Up until this point I was familiar with the sad historical information that he presented. He then carefully outlines the biology of obesity, focusing on two key parameters: insulin and insulin resistance. Although I was somewhat familiar with both topics, he presents them in a way that makes perfect sense, both from a clinical and biological standpoint. Each statement is carefully referenced so the reader could go to the source to learn more. Dr. Fung has a very fluid writing style and his concepts are presented in such a way that both medical experts and novices can easily follow his thinking. When it comes to solutions he presents a well cited summary of the healthiest foods for us to eat and I was already fairly familiar with most of this information. I must admit that in the past I tended to focus on glucose levels because they are easy to measure and follow, but Dr. Fung convinced me that the focus must be on insulin. For example, like most clinicians I had been teaching my patients about the glycemic index and load, which reflect the relative glucose response of various foods. Dr. Fung recommends using the Insulin Index because some foods that do not raise glucose do significantly raise insulin levels and as he points out, it is elevated insulin that leads to obesity and type 2 diabetes. He also points out that in addition to carbohydrates, both protein and fat can sometimes raise insulin levels. For me the most important information in this book is the absolute importance of separating the glucose response from the insulin response to eating. The other important take home message that hit my brain like a sledgehammer is the issue of timing of meals. I hate to say it but until I read this book I never gave the issue of timing of meals much thought. Dr. Fung weaves a fascinating tale about how the timing of eating is the key to reversing insulin resistance. He outlines how intermittent fasting can be easily incorporated into any treatment program to manage common metabolic problems. I should have figured this one out on my own. When I married my Greek wife I also joined the Greek Orthodox Church and as he points out these folks are the masters of intermittent fasting. And by the way, don’t make the mistake of measuring your progress by weight loss alone. There really is no such thing as a “weight problem”. Obesity is defined as excessive body fat so the most accurate way to measure progress is by measuring body composition. Because this type of measurement is not easily available to many people, I recommend keeping tabs on your waist measurement at your belly button. You can also get a rough idea how you are doing by how your cloths fit. If you are noticeably shrinking you are likely losing fat even if the scale isn’t changing much. To summarize, all I can say is if you want to be healthy in today’s world loaded with endless amounts of toxic fake food, you need to read this book. And if like me you also want to read the second best book out there related to diet and health, re-read “The Obesity Code”. It’s so chock full of great information that it’s almost impossible for all of it to sink in on the first read.

My doctor told me to get this book to look at. health in a totally different way and she was right! I like the approact to the idea of obesity being beyond the typical definitions. It was an easy read and great.

Author is MD, an allopath, not told the entire truth about medicine in medical school. A few steps are left out and you’ll never be rid of that ailment. You must have noticed that drs never ever never cure you, they help your symptoms and you keep going back til you die. There’s no money in a cure. Dr Fung realized that something was wrong with the treatment of obesity. That’s what this book is about. It’s great to see an MD leave his backyard and actually help struggling patients. The food today is so toxic, even organic foods are affected. Corporations add so much sugar and salt that it creates lifelong cravings. They were serious when they said of Lay’s, “Betcha can eat just one.” You really can’t. The result is obesity. Once you start adding the visceral fat on your abdomen, the chronic diseases begin. That means $$$ for pharma and medicine. For life. And that’s the plan: to keep you fat, sick and sitting down. I believe your life will change if you follow what Dr. Fung advises. He’s one of the good guys. I hope they don’t take his license for being honest.

This book is going to make you angry. Angry at the government for ignorantly (or politically) making determinations about nutrition and health that turned out to be fundamentally wrong. Angry at scientists for ignoring the data of their own studies to disseminate biased conclusions that we now know are completely false. Angry at organizations like The America Heart Association for allowing its branding to appear on products that are decidedly NOT healthful. (For example, Cheerios has a glycemic load almost as high as sucrose - actual sugar! - and yet the AHA put its Heart Check stamp of approval on it.) Angry at companies that promote foods as a fad, considering shaky scientific evidence as an axiom with its products like “fat free” foods that are almost all sugar, and “gluten free” foods that are only beneficial to a mere 1-2% of the population. Angry at The Biggest Loser, Weight Watchers, Atkins, and all the other diet plans that work for a year and then inevitably result in most people gaining back all the weight that was lost, because the science behind those programs is less important than the money those corporations make. (If you get fat again, just keep sending $15-$25 per month and we’ll help you try to lose it again! And again! And again!) Angry at artificial sweeteners and diet sodas, both of which trigger the same insulin responses as if they had real sugar, but depriving the body of actual glucose, resulting in you craving even MORE diet soda and MORE food. Angry at your parents for telling you that it’s better to eat six small meals each day (even though your grandparents knew better and told your parents that snacking in between meals would make them fat, and that they shouldn’t eat when they’re not hungry). The good news is that Jason Fung explains everything very clearly, so you don’t have to be a scientist yourself to understand this book. He unravels all the factors that make us fat, and gives us solutions for how to rid ourselves of those extra pounds. It’s a difficult read if you’re biased towards six meals a day, fat free, gluten free, calories in equals calories out, the food pyramid, or any of the other beliefs many of us were raised on and continued to be told our whole lives. But once you’ve finished this book, you’ll finally KNOW how to truly fix your fixation with bad food, know when and how often to eat, and - most importantly - truly UNDERSTAND how to lose weight properly without gaining it back. My favorite little gem from the book was learning that “calorie counting” became the government’s recommended method because of Herbert Hoover (as head of the U.S. Food Administration); and George McGovern (as head of the United States Senate Select Committee on Nutrition and Human Needs) decided that dietary fat was bad and carbohydrates were good, resulting in the disastrous Food Pyramid that got everyone to eat large bowls of pasta with a couple of meat balls, which subsequently made 40% of the United States obese! That’s right - POLITICIANS decided in the 70s and 80s what was good for you, and - big surprise - they were completely WRONG! And the fallout from those awful decisions have been with us for 40-50 years. This book will make you angry, but it will give you hope and power - the hope that you CAN lose weight permanently, and the power to do it with legitimate, good science on your side. To quote the master, “you must unlearn what you have learned.” I lost 30+ pounds based on what I read in this book, and I’ve successfully kept it off. You will too if you follow its advice.

Jason Fung is a doctor with a fire in his belly. I came across Jason’s work in January 2015 after watching his How to Reverse Diabetes Naturally video which has now had more than 600,000 views. Jason’s primary thesis is that constantly elevated levels of insulin lead to insulin resistance which causes obesity and a host of metabolic issues. Jason says that fasting, not more medication, or even a low carb diet, is the most aggressive way to reverse insulin resistance. Jason has developed a significant following in a short amount of time due to the fact that he has joined a few fundamental dots when it comes to diabetes, weight loss and insulin. He also doesn’t pull any punches when it comes to communicating the message that people who are producing too much insulin due to hyperinsulinemia and obesity probably don’t need any more insulin. You may think of Jason as ‘that fasting guy who says insulin is bad’ however his work is much more extensive and comprehensive. Inspired by a hunger to understand the situation and how he can help his patients, he created a massive six-part six hour Etiology of Obesity series and an extensive blog for his patients. The Etiology of Obesity series on YouTube is not just about insulin or fasting. It’s a comprehensive review of a plethora of relevant research and theories in the areas of nutrition, weight loss and obesity. But why has a busy nephrologist (kidney specialist) gone to all this effort when he could be making a lot more money treating sick people? It seems he got fed up with treating symptoms and wanted to start addressing the upstream root cause of the diseases that his patients were suffering with. Jason’s new book The Obesity Code is not just about fasting, it’s about the full etiology (causation or origin) of obesity. He has done an excellent job of setting out the multiple facets how obesity develops so we can gain a better understanding of what we can do to remedy that will work in the long term. If there’s one drawback of his videos and previous work, it’s that the production quality of the lectures for his patients don’t do justice to quality of the content. Jason’s new book, The Obesity Code is a polished, professional product that sets out all the research that’s gone into his videos and blog in one cohesive, comprehensive piece of work. There are many factors that affect our metabolic health and lead to obesity. Jason delves into each one and joins the dots between them. - In chapter two Jason talks about the genetic factors that influence insulin resistance. - In chapter three he talks about how the body adapts to energy restriction and thwarts our weight loss endeavours. - In chapter four he talks about how exercise makes us hungry and also doesn’t reliably lead to weight loss. - He talks about how we are educated by food marketing to eat all the time, thus keeping insulin and blood glucose levels high. And on he goes though insulin, cortisol, the pros and cons of low carb, hyper palatable foods etc etc etc. In the end you need to address the thermostat, or the set point, which is controlled by the master hormone insulin. Intermittent fasting is the most effective way to lower insulin and restore insulin sensitivity. Jason covers a wide range of topics thoroughly, logically and with extensive research and references. This is practically a textbook on the different facets of the subject that is easy to read and engaging for the educated layman. It was Jason’s observation about the food insulin index, and the effect of protein and fibre that, after watching his video series, sent me down the rabbit hole to develop the concepts of ‘insulin load’ and ‘percentage of insulinogenic calories’. I wanted to formularise them to see how we could apply them to identify foods that would reduce insulin. Go buy the book. Enjoy! Marty Kendall OptimisingNutrition.com

Before starting this review, a little background on myself: I'm 30 years old and I've been overweight almost my entire life, at one point reaching a high-point BMI of 37 and being extremely obese. Over the last 10 years, I've lost and gained and lost and gained weight up and down in countless ways - high-intensity interval training and paleo and keto and everything in between, but have always struggled to sustain loss and struggled to lose enough to get into a healthy weight range. Over a period of eight months, following the same practices provided in this book, that has finally changed for me - I rapidly lost nearly 50 pounds and have managed to keep it off through holidays, birthdays, and more. As much as I'd love to think this was just me in my older age acquiring a new found sense of extraordinary self-discipline seemingly overnight, it wasn't. It was my body actually *changing* in ways that made it feel natural and normal and healthy to eat well and made it feel unnatural to eat poorly. Dr. Fung's book does an amazing job of dispelling the myths around weight loss being a "self discipline" problem and instead being a hormonal problem. Fix the hormones and you fix the problem. Period. Put another way, there are lots of things we humans do every single day that require extraordinary amounts of discipline, with full knowledge of the pleasure and pain trade-offs of those things, so why is it that food is so hard? Perhaps it's as if our desire to eat or not eat is not actually controlled by our conscious brain and some nebulous idea of psychology, but instead by overwhelming hormonal signals sent by body... This book starts along a path previously explored by a lot of other books and articles, but blends them together in the most understandable and accessible way I've ever come across. Simply put, we all have read somewhere or already believe that a major player in so much of our growing obesity epidemic is insulin, but where Dr. Fung's work differs is that he asserts there are actually two parts of the insulin problem that need to be addressed: 1. Day-to-day insulin levels (In response to what you eat on a given day; this is the thing that gets tackled by diets/lifestyles like ketogenic, which lower your day to day insulin levels by simply consuming fewer forms of glucose) 2. Your body's "set weight point", a concept that refers to the weight your body *wants* to be at and will go to crazy lengths to keep you at, either by making you hungrier, making you restless and ready to move, making you generate more or less body heat, and more. He argues that while we've done a lot to address #1, ultimately it results in what we all know to be true: people regain weight. They don't sustain loss. In order to sustain loss, they need to change their "set weight point" and in order to do that, we need to understand what controls it. Throughout the course of the book, Dr. Fung leads through not just countless studies and experiments, but also plenty of the adages and anecdotes of the past that we've all known but don't spend much time thinking through to conclude that what controls this "set weight point" the most, both directly and indirectly, is our insulin sensitivity or resistance levels. And there's only one way we've found that actually sustainably changes our insulin sensitivity and that happens to be fasting. But don't take it from this review alone - there's so much more depth and so many great things to learn from this book, it is absolutely worth a read for anyone fighting an enduring struggle against weight gain or even those thinking about starting down that path and changing their life.

I found Dr. Fung on youtube and found myself mesmerized by his videos about diabetes and obesity ("diabesity"). I had been an avid low carber for more than a decade after developing gestational diabetes during my first pregnancy at age 29. What a total shock it was for me, a super skinny size 2 woman, to be told I'm diabetic! Thankfully I was able to turn it all around with low carb dieting. When I had my second child at the ripe old age of 37, I did not develop gestational diabetes, to the huge surprise of my doctor. Low carb worked. Fast forward eight years. I fell of the low carb wagon due to work, kids, stress in general and quickly packed on 15 pounds (which is a lot for a 5'4" person). While eating low carb is fantastic, it does require a lot of time and money to prepare appropriate meals from scratch. I thought I could offset the lack of time in the kitchen with more strenuous exercise (HIIT, weights), but it didn't help at all. Then, even when I switched back to hard core low carb, the weight loss was very slow at best, and came to a stall after a few pounds, despite stepping up the exercise regiment. To say I was frustrated is an understatement. I tried to write it off as the inevitable mid-life spread, but was very depressed about it. Then this happened: I went to see my parents and family who live in Germany for two weeks. During those two weeks, I didn't watch my diet at all, didn't exercise at all (except lots of walking), and I LOST 10 pounds! This frustrated me even more, because I could not make sense of it. I ate high carb, high fat foods and just walked around, and the fat melted off of me. When I returned to the States, I regained all that weight within a few months, and then some. I thought I was going insane. Enter Dr. Fung's videos on youtube and his brilliant book, and it FINALLY all made sense. What happened while I was visiting my family was that I inadvertently practiced intermittent fasting. I slept in every morning and all I had was some coffee with half and half, then nothing until late afternoon, early evening for dinner. It was scorching hot during the summer, so I also didn't feel like snacking a lot in between. That way, my insulin levels finally had a chance to drop enough for me to burn my own body fat. Back in the States, I went back to the frequent snacking, and basically stopped the intermittent fasting. The weight came back. Now, I've applied Dr. Fung's findings and lost almost 10 pounds again in less than two weeks with very little exercise. I can literally see the fat come off my body every day. Stepping on the scale is no longer frustrating or scary, but a victorious moment when I see yet another pound come off. I'm not hungry and have to almost force my self to eat once it's time to break the fast. I have also been able to incorporate higher carb foods and treats in moderation, and that alone is amazing to me. Also, I save so much time and money on food shopping, preparation and clean up. Thank you Dr. Fung, we need more docs like you in the health care field. I'm a nurse, and I see so much of what you described in your book and it breaks my heart. Sometimes it makes me question my career choice.

I have so much to say that I don't know where to begin. I am new and just started the fasting. I saw improved results almost immediately. I am taking two shots a day-- victoza and lantus. I hate both of them. I will admit I have not been a great patient with the meds -- metformin not a problem but the shots are. Along came Dr. Fung's book. In two weeks, I noticed results immediately. I had not seen my endocrinologist in 6 months. (They are hard to find where I live and I had to cancel one appt. and it took 3 more months to get another.) I was thrilled to start Dr. Fung's Intermittent fasting and thought my specialist would have to agree. She didn't. In fact, she discharged me from her care yesterday. In spite of the good results and cutting my insulin in half over the last two weeks, she wrote a discharge letter to my primary care doctor stating that I am non compliant. She even quoted me in the letter, when I told her about the fasting idea/concept. I had printed off several copies of interviews with Dr. Fung. She didn't look at them. She will no longer treat me. Why? Because I mentioned IF therapy. Prior to starting with the fasting my numbers were in the 300s with no medication. I started the fasting and am using half of my meds, and I so pleased about that. I just thought she would share my enthusiasm. Instead, all I got was the " I follow the guidelines of the ADA". I am just so frustrated - Her last words were "Lantus is your friend. Do not make it your enemy". I explained that I cannot lose weight on it and that I dislike the 2 shots a day I am taking and that it is keeping me fat. She didn't want to hear it. So in closing, I will have to go about this on my own and manage my diabetes through the book and without her help. We live in an area where there are so few specialists for diabetes and it takes a long long time to get an appt. Now she has written me off as if I am a bad patient not following orders. I feel like Elaine on Seinfeld- remember that one? The doctors all wrote each other notes about her bad behaviour. Wish I could be treated by Dr. Fung. Any advice?

My assessment of the book is colored by what has worked well for me for the last twelve years. I am 6'2" and have hiked or cross-country skied several days a week every week all year for the last 35 years, so exercise has been more or less constant. Up until about twelve years ago, I gained a pound or two a year, gaining 35 lbs., mostly around my middle. At that point I weighed 205 lbs and my waist size had grown up to 38". I lost the excess 35 lbs in about a year, twelve years ago, and have not gained any of it back in the last twelve years, somewhat to my surprise. My waist size has remained constant at 31" since I lost the weight and had to discard all my old pants. Comparing what worked for me with the author's points results in a good deal of agreement, but also areas where I am not yet convinced that he has it right. I do heartily agree with him that a long term view is needed. Anyone can lose weight in the short term. Maintaining an ideal weight and body composition consistently for many years following years of overweight is infinitely rarer. What is especially lacking from the book, and perhaps lacking from the medical literature, is illumination of pathways that have actually resulted in ideal body composition numbers consistently for many years, in real life, after many years of being at least several tens of pounds overweight. The protocol that I adopted over twelve years ago and have refined over the years is essentially the "Paleo" diet. I eliminated every trace of gluten and wheat from my diet, when previously my staple food was homemade whole wheat bread made from home ground wheat. I eliminated all dairy except for rare indulgences. My diet changed to consist of lots of home-prepared salmon, sardines, seafood, grassfed beef, poultry, lots of greens and vegetables, high quality olive oil, coconut oil, macadamia nut oil, avocado oil, some sweet potatoes, and dark chocolate. Fruit is mostly limited to modest quantities of low sugar berries. It is hard to find restaurant food or fast food consistent with these limitations, so eating out is usually once or twice a month. Since making the dietary switch, I haven't had a problem with being particularly hungry and despite what the author suggests, I not only did not ever tend to revert to my prior weight, but my body composition seemed to pull toward ideal and stay there. If I had just stayed on my prior weight gain trajectory, I would now weigh 230 or 235 lbs instead of 170. The author may differ from me in his assessment of dairy products. He goes to some length to target high insulin levels and insulin resistance as central to developing and maintaining obesity. And he also acknowledges that dairy products such as milk provoke high insulin levels. Indeed, studies also show that they provoke insulin resistance, even in non-diabetics. But based on studies which included many confounding factors and very modest end point weight differences, he seems to conclude that dairy consumption does not contribute to obesity problems, contrary to everything else he suggests regarding insulinogenic substances. In nature, milk is designed for one purpose, to make baby cows grow as big and fast as possible. The risk in adult humans, for whom is was not designed, is that milk may have a similar effect. I like dairy, it is very convenient and cheap, but it is far from ideal food on a regular basis for adult humans wishing to avoid insulin resistance. When I gained my excess weight, my intake of sweets and sugar was relatively modest. Despite lots of exercise, I gained my weight eating lots of homemade whole wheat bread. Though I am not celiac and do not have celiac genetics, I developed severe reflux and other health issues that disappeared for the long term when I went strictly gluten free. Even whole grain bread was enough to push me well on my way to obesity. Another intervention that I made and have kept is elimination of monosodium glutamate and other similar excitotoxins with various names such as autolyzed yeast. These are food additives that manufacturers add to processed food. They have no nutritional value, but are designed to trick the brain into thinking that the food tastes better and to induce more food consumption. Some mouse studies link them to neuronal damage and development of major obesity, and there is no need for them. The book makes many good points, and indulges in some speculations and extrapolations based on those points. The book relies heavily on peer reviewed studies of humans. But so did the discredited dietary conclusions that held sway for decades that the book assails. Some day, who knows when, the science will be sorted out. What the book may lack is a clear pathway for reaching desired healthy body composition in real life, for the rest of one's life. To some extent, while the science develops, it may be that the best we can do is look to nature for that pathway. I've seen thousands of deer and a number of mountain lions. I've never seen an obese deer or an obese mountain lion. I assume that this is because they eat what nature evolved them to eat. I've endeavored, in the meantime, to ask what humans evolved to eat. I suspect that if humans eat what they evolved to eat, obesity in humans will be no more common than it is in deer or mountain lions.

I don’t typically read diet books but this one caught my eye because of the positive reviews. I was not disappointed and am writing this review after my second read several years later. The book does a great job of showing why weight gain is a hormonal problem and not one that is simply solved by reducing calories, eating low fat, no carbs, etc. It’s all about what you eat and when you eat. My big takeaway is its 70% genetics, 25% diet, and 5% exercise. I used intermittent fasting to avoid weight gain during COVID and after a back injury. Before my back injury I ran 20 miles a week. You would think that not running would cause me to blow up like a blimp. That was not the case. Without exercising and practicing fasting I lost weight during COVID. It is now a part of my life and like the author said has simplified it.

I started reading this book this February at 293 pounds. I put into action the recommendations in March and have since lost 90 pounds (203 Baby!!!) My energy is up, my clothes are too big ( I can honestly say I have never bought clothes and then have them not fit two months later because I shrank! ) and all I can say is... Thank you Dr Fung. You changed my life. My numbers are down I am no longer pre-diabetic. My back no longer hurts. Life is beautiful. I would like to state that I am an impatient person and did do a few 7 day fasts. Other than 3 of those though all I have done is intermittent fasting and cut out most processed foods and now only drink water. I did not even start working out until 3 weeks ago. In six months I have made more progress than I have made in 6 years. And the best part? It's easy. I am not going to stop because I have no desire to. Oh I have my cheat days where I eat a whole bunch of sugar cookies for desert. But I still only eat once a day and the weight keeps falling off!!!! If you are diabetic or pre-diabetic, read this book. If you are overweight, read this book. Heck if you just like to point your finger at our health system and state how idiotic it is READ THIS BOOK!!! I am not exaggerating. This book is not a gimmick. I loved this book so much I actually bought it after I read it at my library and then bought it's sequel The Complete Guide to Fasting. Do not state that you cannot do it. You have not truly tried. Everyone can fast. Yes the first week may be hard ( I am pretty sure I had a candida overgrowth and felt like I was dying, fun times) but it doesn't last! Don't let yourself get to the point I was at of being in constant chronic pain, brain fog and just plain tired all the time!!! Take control of your life and show your friends and family that there is a way to lose weight and be happy. You don't need to be in pain, you can gain a better life.

Should be read in conjunction with The Diet Myth by Tim Spector. Here are my takeaways from both books, starting with The Obesity Code: 99% of the time [my number], any struggle we have with health and wellness is a result of two types of imbalance: - Imbalance of fat hormones, primarily insulin (The Obesity Code) - Imbalance of the gut microbiome (The Diet Myth) -1% of the time [again, my number], our struggles come from outside forces, including genetics and unpreventable illness Imbalance of fat hormones can be solved by these few things: - Reduce or eliminate snacking - Reduce or eliminate consumption of refined carbohydrates, refined sugar (including fruit juices), and processed foods. No consumption before 5 p.m. is a good way to accomplish this - Balance consumption of carbohydrates with consumption of fats and proteins - Eliminate consumption of artificial sweeteners which signal to the body that you are eating calories when, in fact, you are not - Narrow your eating window to 8-12 hours to give your body a long break from insulin and a dose of growth hormone - Avoid fast food (for a number of reasons, but primarily the lack of buildup to putting calories in your body) - Make breakfast optional (or less than 50 calories) - Experiment with intermittent fasting and decide what works best for you - Improve sleep hygiene by maintaining a regular sleep schedule, sleeping in complete darkness, not using electronics before bed, and not using caffeine or alcohol - Decrease stress by meditating, increasing exercising, and spending time with people who make you happy - Maintain a long-term approach to hormone imbalance. If you can improve your insulin intolerance by 1% per day, you’ll be doing great in a few months. Most people gain 1-2 pounds a year, so why do we think it’s healthy to lose 1-2 pounds a week? Imbalance of the gut microbiome (The Diet Myth) can be solved by these few things: - Eat a “Mediterranean diet” including primarily plant-based foods, such as fruits and vegetables, whole grains, legumes, nuts and olive oil. Spending three weeks on an elimination diet will help get you started with this (excluding dairy, soy, nuts, eggs, grains including corn products, and refined sugar) - Increase the diversity of your diet by aiming for 20-30 different types of fruits, vegetables, whole grains, legumes, and nuts per week - Eat meat sparingly. Vegetarian before 5 p.m. is a good way to accomplish this - Eat seasonal produce - Incorporate raw foods into your diet to replenish your gut microbiome - Increase your consumption of prebiotics, including lemon peel, raw garlic, and raw onion - Increase your consumption of probiotics through things like sauerkraut, plain Greek yogurt, kimchi, kombucha, pickles, and “live” cheeses - Don’t disinfect everything you see - Reduce or eliminate consumption of refined carbohydrates, refined sugar (including fruit juices), and processed foods. No consumption before 5 p.m. is a good way to accomplish this - Maintain a long-term approach to wellness. If you can improve your gut microbiome by 1% per day, you’ll be doing great in a few months You’ll notice I didn’t say anything about calories and little about exercise. These are sort of red herrings and you should consider them a small part of the equation. If you follow the above suggestions, you probably won’t have to worry about calories. And, as a bonus, you’ll feel so good that exercise will come naturally as a form of play!

Less insulin = more health! So simple!!! This should be a textbook required for every semester from preschool to PHD. Time to stand up and fight back against a heartless system that is making you sick and taking your money. Stop the madness and get a grip on your health!!! I have first hand experience in fasting AND eating only real food. Just because sugar tastes good does not mean it's food!! It's actually very counter productive. And ALL the man made concoctions labeled a food are actually just robbing you. Open your eyes and see whats happening. If you give up all sugar, all processed "foods" and eat as nature has provided then you will glow. In all my search for answers this book has put it all together in one place. It's true that once you've gone 24 hours without eating anything your stomach goes from a ravenous lion to a meek quiet kitten. Not hungry at all. It's true that once you convert to burning fat (only) you get more energy and more mentally focused. Surprisingly at 24+ hours fasted I don't really even want to eat because I'm feeling so awesome. Almost out of body experience. Just vibrant!! Honestly the best explanation of what's gone wrong and the solution to fix it. Give yourself a gift and read this book. You will be better for the rest of your life.

What it's for: This book should be required reading for all physicians. It makes SO. MUCH. SENSE. Yet it flies in the face of accepted "conventional wisdom." There were several times I had to actually put the book down for a minute as the discomfort of having well-ingrained "truths" debunked was at times so visceral. Mind-blowing, yes. Paradigm-shifting, yes. Highly recommended for anyone who has ever: struggled to lose or gain weight, watched someone else struggle with weight, had emotional attachments to (or against) food, been confused about "good" vs "bad" foods, tried to move more and/or eat less, watched what they ate, counted calories/macros or tried diets or eaten food or lived in a human body (did I miss anyone?) It is seriously amazing to me that we continue to believe (well-funded) myths about how our bodies work and even "experts" continue to encourage practices that not only don't work but often actually run completely counter to how our bodies are designed. What it's not for: If you want to know "what and why," this book will tell you; for the "how," you'll need to read something else (I highly recommend Gin Stephens' "Delay, Don't Deny" and "Fast. Feast. Repeat." to learn how to implement the principles Fung teaches.) If you don't want to be bothered by the science and how the insulin cycle works, and you're willing to go completely on faith that it's true, I guess you can skip this and go straight to Stephens, but if you're like me and you need/want to understand what is happening and why, this book is a really great foundation. (However, I would posit that if you are wanting to just skip to the "how," you would probably benefit from slowing down your expectations and forcing yourself to truly understand what is happening...it will help you more in the long run if you grasp the underlying principles.) I started this book after a friend mentioned it and I was just curious. As I said, it was kind of mind-blowing. After reading, I knew I wanted to try it and that led me to Gin Stephens, who makes the path clear. I had no exact intentions or goals, but jumped in, worked through the transition and am still surprised at how easy it is and what a difference it is making in my life and health. I have lost weight, yes, and will continue to, but it just feels like life, not a "diet." I am working with my body's natural processes and it's very freeing to feel that way, instead of feeling like I need to fight--fight cravings, fight weight gain, fight tired cycles, fight "bad" foods, fight guilt, fight negative body image... If you are looking to learn about your body actually works or are tired of fighting--this book is a good place to start.

UPDATE 6/22/18: I am still following the advice of the author. On Father's Day, I had a feast, which included cobbler and ice cream, although I still limited my meals to 3 that day. The excess sugar suspended weight loss for exactly 48 hours, but once resumed it has been steady. As of this morning, I weighed 173.4, which is nearly 7 pounds in 9 days. This is a record for me, in terms of pounds lost in a week. Second, I am amazed because my circumstances are not all that conducive for weight loss but it is occurring anyway. Yesterday, I weighed LESS immediately after dinner than I did first thing in the morning. So exciting and encouraging! ORIGINAL REVIEW 6/13/18: I bought this book because I wanted to learn more about insulin resistance. Both my father and grandfather developed Type 2 diabetes about the age of 50 and died at 59. My father, however, immediately lost 50 pounds, kept the weight off, and never needed insulin shots (cause of death was COPD). I recall the only change he made was to quit eating sugar. In fact, my family is a bit unusual in that several members lost weight in their 40's and 50's and kept it off, including my mother who decided decades ago to quit eating after 6 p.m. At one point, I had weighed 215 pounds (standing at 5'4) but got down to 145. While I have never come close to that weight since (it`s been 12 years), I was alarmed when the scale read 180 last week, but was just 172 a couple of weeks before that, and 163 two months ago. What I eat hasn't changed much over the years but the frequency of snacks and meals has. I had been following the advice of Dr. Amen who said you should not go any more than 3 hours without eating. This book, however, says that eating too often during the day does not give insulin levels a chance to become lower, which I only just read 2 days ago. I followed the author's advice to stretch the time in between meals and to forgo snacks. When mealtimes came around, I ate as I normally do, not concerning myself with counting calories or restricting fat. I am a perimenopausal, almost 47-year-old woman, who at present is exercising very little because I am getting very little sleep these days. EVEN SO, following this author's advice, I have lost 4 pounds in the last 48 hours. I skipped lunch yesterday but weighed myself at noon. I weighed 178.2. Minutes after I ate dinner (which included dark chocolate squares for dessert), I weighed myself again. I weighed 178.0. Food does not make us fat. Insulin does. Clearly my body is now utilizing food as it should. I am observing the same phenomena today. Interestingly, I also did not suffer from any type of joint or muscle pain yesterday, either, which is normally problematic for me. There is no one-size-fits-all solution to weight loss but if you are willing to read a book like this and examine the pieces of the obesity puzzle, it is possible to come up with some answers that have eluded you for so long.

It's really amazing to learn that we've known the answer for at least 50 or 100 years but keep burying it in the context of profit and corporate interests. To the people who write things like "But there is no proof not eating for twenty four hours works any better than low calorie diet:" Did you even read the book? Fung mentions study after study that shows the effects of low calorie diets being adapted to by people over time. Have you tried fasting after reading this book? It's just like he describes. You don't get as much of the weird physiological effects as you do from just reducing calorie intake while still eating 3 meals a day. If you can adapt over a week or two to eating just a meal a day, you'll see just how much energy you have, how little you're actually hungry during the day, and how satisfying a healthy meal is when you do eat. I'm following the one meal a day strategy with a little dark chocolate as my dessert. I've lost about 8 pounds in 9 days. Yes, most of this will be water weight at first, but there's no denying that I feel my insulin sensitivity is improving. My blood pressure has gone down, my resting heart rate has gone done, and I no longer feel ravenous after exercising. For example, I had lunch yesterday, then played 2.5 hours of tennis in the evening, and then did NOT eat until lunch today. I had a large salad with a filet of grilled fish, and then maybe 25 grams of 70% dark chocolate afterward. Felt great and didn't feel bogged down like I would after eating something more carb-heavy like a sandwich or a burrito. Overall, most of the 1-star reviews i see for this book have to do with technical issues, a lack of reading comprehension, an inability to read the book, and a skepticism of science. Personally, I found the book riveting. The context in the first 100 pages helps disavow you of the flawed notions of nutrition and lays the groundwork for explaining why the positive strategies (mentioned later) work. Love love love.

Great book! Enjoyed the whole thing! Very interesting, educational and informative. Dr. Fung writes in common words covering advanced topics.

I followed Dr. Fung's intermittent fasting combined with low-carb/high (moderate) protein and lost 23 lbs. in four months. My sleep apnea disappeared, my snoring stopped, my energy skyrocketed, my blood pressure and fasting blood sugars went down, my cholesterol and trigylcerides went down. I lost belly fat and had to get news pants. I feel like I new man. This book is an education, not just a list of instructions. In fact, the "how to" is so simple and straightforward that it takes up a small part of the book and is placed at the very end. Simply put, it's knowing What to Eat and When to Eat. The bulk of the book is "why?" we need to do both - look at the kinds of food we eat and when (how frequently) we eat. He explains that obesity is about the body's regulation of insulin. Full stop. Control how much your insulin is elevated by the foods you eat and how long it stays elevated by how frequently you eat, and you can lose and maintain a healthy weight. He spends a lot of time on the science of insulin, debunking and disproving the overly simplistic "it's all about calories" idea of weight loss, other received "wisdom" about weight loss, and explaining why so many diets - even very healthful ones - always seem to fail. This book gets into the science of obesity without it being a tough read. In fact, Dr. Fung's great sense of humor shows through in every section. He reminds us that billions of people across the globe have regularly fasted for religious reasons for millennia and they tend not to be fat, or suffer any problems from the fasting. It's normal. Our bodies were meant to go for significant periods unfed. Remember how we used to have regular meal times and "no snacking" rules? Well, for this very reason just a few decades ago, obesity was pretty rare. Now its everywhere, because we are eating a lot of processed junk and eating all of the time. We never allow our insulin levels to go down, and insulin is the main driver of obesity. This is a fantastic book by a real doctor who really cares. He isn't selling anything beyond knowledge to learn how and when to eat for health. Please do yourself and those you love a favor and get this book.

As someone who has lost 80 lbs and kept it off for 2+ years, I read a lot on obesity, low carb, paleo, diet du jour etc. But The Obesity code, is teaching me a lot of things I did not know. It isn't a self-help, how to, diet book. It's mainly facts backed by research laid out in an easy-to-read compelling manner. I would highly recommend it if you would like to learn more. I've recently put on about 6-9 lbs and wanted to lose them before the regain got out of hand. I cut calories once again but after a month of low calories and low carbs, my weight had not shifted at all. At my wit's end, I started to look around again, to try to learn more. I was fairly sure what had happened was that my body has adjusted to chronic low calories. But I don't buy into the "don't skip a meal" theorists, because frankly, I don't know of anyone who has lost weight without eating less, or eating differently than before. The nutritionist I saw wanted me to eat more, and eat more carbs, but it's hard to do that when you're already not able to lose weight. This book was very informative. Based entirely on human studies, backed by solid research, and clearly distinguishing between correlation and causation, it educated me and is making me question several of the things that I have been doing, such as cutting calories too low, protein shakes, fake sugar, etc. I didn't know for example, that low glycemic index foods, while great for your blood sugar, can still raise your insulin. So I've been consuming artificial sweeteners, without realizing that sugar raises your insulin less than do some of those sweeteners. Who knew. On my blog, twosleevers, I've listed 7 things I need to do differently, after reading this book. He cites multiple studies that show that a 30% reduction in calories will result in a more than 30% reduction in basal metabolic rate. In other words the less you eat, the less your body needs. Often referred to as Adaptive Thermogenesis, this is yet another instance of how our bodies develop compensatory mechanisms to cope with adverse situations. This would explain why so many of us who have lost weight by cutting calories before, are now struggling with weight gain on very low calories. His main premise is calories don't cause weight gain, insulin does. Most of the strategies center around how to control high insulin, and insulin resistance. He emphasizes not just what you eat (whole foods, no sugar, no processed foods etc.) but also when you eat. Fasting plays an important role in increasing insulin sensitivity, and he has several recommendations around how and why to incorporate this into your life. It's not that the final recommendations he makes are drastically different from what all of us who chronically fight our weight know--it's that he carefully and consistently explains why things happen the way they do, which allows a rational person to extrapolate from what is learned, to apply to their own life. I also like his framework of the pathways to obesity, which explains some of the more likely suspects for weight gain, and allows you to adopt a multi-pronged attack to address your own issues. All in all one of the best books I've read on this topic, and the fact that the last 30% of the book is citations pleases my geeky little heart.