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.