Jason Fung Net Worth Overview

Dr. Jason Fung didn’t invent fasting—humans have fasted for millennia. But he made it mainstream medicine. His estimated net worth of $5-10 million reflects his position as perhaps the world’s most recognized authority on therapeutic fasting for type 2 diabetes and obesity. Among the health guru net worth rankings, Fung represents the physician-author who turned clinical experience into a publishing and coaching empire.

As a nephrologist (kidney specialist), Fung watched patients progress from type 2 diabetes to kidney failure—a preventable trajectory, he believed, if doctors focused on root causes rather than symptom management. His controversial thesis: type 2 diabetes is a dietary disease that can be reversed through fasting and low-carbohydrate eating, not just managed with increasing doses of medication. This message, delivered through bestselling books and the Intensive Dietary Management program, made him a hero to millions who felt the medical system had failed them.

His wealth comes from multiple bestselling books including “The Obesity Code” and “The Complete Guide to Fasting,” The Fasting Method coaching program he co-founded, and collaborations with platforms like Diet Doctor. Whether you view his approach as revolutionary or oversimplified depends on your perspective—but his impact on how people think about food timing is undeniable.

Who Is Dr. Jason Fung?

Jason Fung was born in 1973 in Canada. He earned his medical degree from the University of Toronto and completed his residency and fellowship in nephrology at the University of California, Los Angeles. He returned to Toronto where he continues to practice as a kidney specialist.

His path to fasting advocacy came through frustration. Nephrologists see the end-stage consequences of metabolic disease: kidneys destroyed by decades of poorly controlled diabetes. Fung began questioning why medicine focused on managing blood sugar with medications rather than addressing the underlying insulin resistance. When he started recommending fasting and dietary changes to his patients, he saw results that medications hadn’t achieved—including patients getting off insulin entirely.

This clinical experience became the foundation for his public teaching. Unlike influencers who learn about fasting from books, Fung has treated over a thousand patients with these protocols, giving him credibility that purely media-based health personalities lack.

Professional Credentials

Fung is a Canadian nephrologist board-certified in internal medicine and nephrology. He completed his training at UCLA and practices in Toronto. He co-founded the Intensive Dietary Management (IDM) Program, now called The Fasting Method. He serves as director of the non-profit Public Health Collaboration and is an advocate of functional medicine approaches.

How Dr. Jason Fung Makes Money

Fung has built a diversified income structure that extends well beyond his clinical nephrology practice. His approach mirrors other physician-authors like Mark Hyman who translate clinical experience into books, programs, and coaching platforms.

Book Sales and Publishing

Fung has authored or co-authored numerous bestselling books on fasting and metabolic health. “The Obesity Code” (2016) became his breakthrough, explaining the hormonal theory of obesity and why conventional calorie-counting fails. “The Complete Guide to Fasting” (2016), co-authored with Jimmy Moore, provided practical protocols. “The Diabetes Code” (2018) focused specifically on type 2 diabetes reversal. “The Cancer Code” (2020) extended his metabolic framework to cancer prevention.

Additional titles include “The PCOS Plan” (co-authored with Nadia Pateguana), cookbooks for both obesity and diabetes protocols, and a fasting journal. With books translated into multiple languages and millions of copies sold, publishing generates substantial ongoing royalty income—likely several hundred thousand dollars annually based on industry standards.

The Fasting Method

Co-founded with Megan Ramos, The Fasting Method (formerly Intensive Dietary Management) offers coaching programs at multiple price points. The platform provides self-guided programs with app access, small group coaching sessions, and individual health coaching with personalized fasting and nutrition strategies. This subscription and coaching model creates recurring revenue from dedicated followers.

Diet Doctor Collaboration

Fung contributes regularly to Diet Doctor, a leading low-carb and keto education platform. His articles, videos, and courses on the platform extend his reach while creating additional income through content partnerships.

Speaking and Consulting

Fung speaks at low-carb conferences, health summits, and medical education events worldwide. His appearances at events like Low Carb Denver and various international conferences command speaker fees typical for physicians of his profile—likely $15,000-40,000 per keynote.

Companies, Products, and Investments

Fung’s business model centers on education and coaching rather than supplements or products. This distinguishes him from practitioners who monetize through direct-to-consumer product sales. Among doctors in the longevity space, he represents the coaching-first approach.

The Fasting Method

This is the centerpiece of Fung’s business empire. Co-founded with Megan Ramos (who has her own remarkable health transformation story), the program offers three tiers of service: self-guided fasting programs with app access, group coaching sessions, and individual coaching. The platform emphasizes community support, recognizing that changing eating patterns is as much psychological as physiological.

Public Health Collaboration

Fung serves as director of this non-profit organization focused on promoting evidence-based nutrition and lifestyle interventions. The organization advocates for policy changes and medical education reform to prioritize dietary interventions over pharmaceutical management.

Media, Books, Shows, and Partnerships

Fung’s media presence emphasizes education over entertainment. His content tends toward detailed explanations of metabolic science rather than the personality-driven approach of some health influencers.

The Obesity Code Series

“The Obesity Code” became a phenomenon in low-carb and fasting communities. The book explains Fung’s thesis that obesity is fundamentally a hormonal problem—specifically, insulin resistance—rather than a simple calorie surplus. It argues that when you eat matters as much as what you eat, making fasting a powerful intervention.

The book spawned companion titles: “The Obesity Code Cookbook” provides practical recipes, while the diabetes-focused titles extend the framework to metabolic disease management.

Diet Doctor Partnership

Fung maintains an ongoing partnership with Diet Doctor, contributing articles, videos, and educational content. This platform reaches millions of people interested in low-carb and ketogenic approaches, extending Fung’s reach beyond his own channels.

Podcast Appearances

Fung has appeared on numerous health podcasts, though he maintains a lower media profile than some contemporaries. His approach tends toward substantive interviews rather than promotional circuits. He has appeared alongside Dr. Mindy Pelz and other fasting advocates.

Controversies and Criticisms

Fung’s bold claims about type 2 diabetes reversal have attracted both enthusiastic followers and scientific critics.

His book “The Obesity Code” received a 31% score for scientific accuracy from Red Pen Reviews, a site that evaluates health books. Reviewer Seth Yoder commented that several main claims are poorly supported by science, including the idea that elevated insulin is the primary cause of obesity. The review concluded that while intermittent fasting may be useful for weight loss, “most people will” not see the dramatic results Fung describes.

Some critics argue that Fung oversimplifies the science of obesity and diabetes. While insulin clearly plays a role in metabolic disease, most obesity researchers view it as one factor among many, not the single cause Fung emphasizes. Renza Scibilia, writing in Clinical Diabetes, commented that Fung’s belief that all current evidence-based treatments are wrong for type 2 diabetes is “an untrue assertion.”

His suggestion that fasts of up to a month have “nothing wrong” with them has raised safety concerns. Extended fasting can be dangerous without medical supervision, particularly for people on diabetes medications or with other health conditions.

Supporters counter that Fung’s clinical results speak for themselves. Patients who have reversed their type 2 diabetes under his protocols become passionate advocates. They argue that mainstream medicine’s focus on medication management has failed millions of people, and that Fung offers a genuine alternative grounded in clinical experience.

Frequently Asked Questions

Sources

1. Wikipedia. “Jason Fung.” Accessed January 2026. wikipedia.org
2. Dr. Jason Fung Official Website. doctorjasonfung.com
3. The Fasting Method. thefastingmethod.com
4. Diet Doctor. “Dr. Jason Fung, MD.” dietdoctor.com
5. Penguin Random House. “Complete Guide to Fasting by Jason Fung.” penguinrandomhouse.com
6. Barnes & Noble. “The Complete Guide to Fasting by Jason Fung.” barnesandnoble.com