Jason Fung, MD, is a Canadian nephrologist and world-renowned expert in intermittent fasting and low-carb nutrition. He is the author of best-selling books including “The Obesity Code” and “The Diabetes Code,” and co-founder of The Fasting Method, where he helps people use evidence-based nutrition strategies to prevent and reverse chronic disease.

Dr. Jason Fung joins host Jocelyn Rylee on the CrossFit Podcast to unpack the myths and realities of fasting, obesity, and the role of hormones in nutrition. He explains why “starvation mode” is misunderstood, why calories alone don’t tell the full story, and how hunger — not willpower — is at the center of sustainable weightloss.

The conversation covers fasting as a therapeutic tool, the risks and uses of drugs like Ozempic, the dangers of ultra-processed foods, and the influence of our environment on health. Fung also shares insights from his upcoming book, “The Hunger Code,” which explores the three types of hunger — homeostatic, hedonic, and conditioned — and how to address each.

Topics Covered

• Myth-busting “starvation mode” and fasting


• Calories vs. hormones


• Insulin, GLP-1, cortisol, and the hormonal drivers of fat storage


• Ozempic, risks, misuse, and ethical prescribing


• Ultra-processed foods and the rise of food addiction


• The role of environment and social influence in obesity


• Practical strategies: satiety, whole foods, fasting, and community

Resources Mentioned

• Jason’s YouTube channel and website 


• Jason Fung’s books: “The Obesity Code,” “The Diabetes Code,” “The Cancer Code,” “The PCOS Plan,” and upcoming “The Hunger Code”


• CrossFit Health lecture: “Fasting as a Therapeutic Option” (2019)


• New England Journal of Medicine study on social influence and obesity

Community Highlight

In 2023, Megan Mulvey walked into CrossFit PTC looking for a challenge. She had no idea she was preparing for the fight of her life.

Just months later, she was diagnosed with leukemia. After 51 rounds of chemo, a bone-marrow transplant, and months in and out of the hospital, her doctors told her, “You were preparing your body, and you didn’t even know it.” As she put it, “CrossFit didn’t just change my life; it saved it.”

When she returned to the gym, she’d lost her muscle — but not her spirit. Her community rallied with fundraisers, rides to treatment, and daily check-ins.

Now, Megan’s paying it forward. She launched Box of Hope, a nonprofit supporting CrossFit athletes and families facing cancer. Their first effort helped a local family cover their mortgage and car payment while their daughter battles terminal brain cancer.

“If I had to go through the worst,” Megan says, “I’ll make sure others don’t go through it alone.”

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