The Obesity Code: Unlocking the Secrets of Weight Loss (Why Intermittent Fasting Is the Key to Controlling Your Weight)

Dr. Jason Fung

Mar 2016 · Dr. Jason Fung Code Book 1 · Greystone Books

About this ebook

FROM NEW YORK TIMES BESTSELLING AUTHOR DR. JASON FUNG—the physician widely credited with popularizing intermittent fasting for weight loss—comes the landmark book that is helping millions around the world achieve natural, sustainable weight loss.

The Obesity Code is a groundbreaking, science-based guide to lasting weight loss that goes beyond “calories in, calories out.” Instead of blaming lack of willpower, practicing physician Dr. Fung explains how hormones—especially insulin—drive weight gain, cravings, and stubborn belly fat. If you’ve tried countless diets and always regain the weight, this book shows you why, and what to do differently.

Drawing on clinical research and real patient success stories, The Obesity Code reveals how insulin resistance and constantly elevated insulin levels lock your body into fat-storage mode. Traditional low‑fat diets, frequent snacking, and severe calorie restriction can actually make things worse, slowing your metabolism and increasing hunger. Dr. Fung shows you how to work with your biology instead of against it, so you can lose weight naturally and improve your metabolic health.

Dr. Fung is often cited as the founder of intermittent fasting for weight loss. Rather than another restrictive fad, intermittent fasting is a flexible, practical tool you can adapt to your lifestyle. You’ll learn:

• How intermittent fasting helps lower insulin and unlock stored fat
• Different fasting methods (including 16:8, 24‑hour fasts, and more)
• How to start safely and manage hunger, social events, and busy days

In addition to when you eat, Dr. Fung explains what to eat for sustainable, natural weight loss. The Obesity Code emphasizes:

• Whole, unprocessed foods instead of ultra‑processed snacks
• Minimizing sugar and refined carbohydrates that spike insulin
• Including healthy fats, quality protein, and fiber‑rich vegetables
• A realistic, adaptable approach rather than a rigid, one‑size‑fits‑all diet

Whether your goal is to lose weight, reduce belly fat, reverse pre‑diabetes or type 2 diabetes, or simply improve overall health and wellness, The Obesity Code provides clear explanations and actionable steps. It’s ideal for readers who want to:

• Lose weight naturally
• Learn how to intermittent fast for weight loss
• Reverse insulin resistance
• Gain science-backed weight loss information

If you’re tired of yo‑yo dieting, conflicting diet advice, and short‑term fixes, The Obesity Code offers a clear, evidence‑based roadmap to lasting change. Learn how to rebalance your hormones, use intermittent fasting effectively, and finally achieve the healthy, sustainable weight loss you’ve been looking for.

Ratings and reviews

Written by an internal medicine specialist this book puts forth that the "eat less and more more" and low fat philosophy that has been recommended for so many years, and that has failed repeatedly (as any dieter knows), is just plain wrong. He also cites many studies to back that up. The author contends that it is not as simple as calories in/calories out, although that is part of the mix. He contends that insulin and insulin resistance are the main reason that we are obese. To combat this he recommends several things such as cutting out all snacks, removing as many processed foods and added sugars as possible, reducing overall carbohydrates and fasting to both regulate insulin levels and reset your set weight. There is a lot to like in this book but the author sometimes simplifies things a little too much, such as using the BMI scale's obesity as his measure for health. That said this is a very good book overall.

I'm just amazed by this book so much, there is greatness in every chapter. You learn so much about your body and it helps you separate the myths from facts. My eyes were open about so many things after reading this book. Now I'm off to read Dr. Fung's second book, "The Complete Guide to Fasting", I started reading it already, it looks very promising, I recomend it too. I recomend anything Dr. Fung has from books to videos and everything else, He is just amazing.

I started to read this book and it's changed the way K not only look at dieting but it's changed my life and lifestyle. I've lost 75 pounds on 6 months in the healthiest way possible. My body feels and looks amazing! I truly feel like it's finally working for me instead of against me. I eat when I'm hungry and simply don't eat when I'm not. the hardest thing was changing my mindset and blocking out the negative points of view that the people around me can't believe or understand. I've recommended this read to almost everyone as I feel it quite possibly has changed and saved my life. Truthfully I never write a review but I feel so strongly about this book I'm taking the time. Also the first thing I did prior to reading was read some reviews. If my review could help save a future me then here it is. Don't quit the inner you is just crying for you to educate yourself.

About the author

Dr. Jason Fung is a New York Times-bestselling author whose books include The Obesity Code, The Hunger Code, The Diabetes Code, The Obesity Code Cookbook, The PCOS Plan, Life in the Fasting Lane, and The Complete Guide to Fasting. Dr. Fung completed medical school at the University of Toronto and a fellowship in nephrology at the University of California. Dr. Fung is also the co-founder of The Fasting Method, a program to help people lose weight and reverse Type 2 Diabetes naturally with fasting. He lives in Toronto.

Timothy Noakes is Professor of Exercise and Sports Science at the University of Cape Town, a marathon runner, and the author of the bestseller The Lore of Running. After discovering research supporting a high fat, low carb diet as the healthiest option for many people, he started the Noakes Foundation in 2012, and has dedicated his life to opening people's eyes to the myth of low-fat eating and the nutritional and environmental crisis it has led us to.