Is Obesity a Willpower Problem? The Biology of Weight, Diets, and GLP-1s

Obesity roughly tripled in about 60 years, and the genes didn't change in that time. So if body weight isn't a willpower problem, what is it? Dr. Jordan Feigenbaum and Dr. Austin Baraki walk through what actually sets your weight: the adoption and twin studies behind the genetics, the "defended range" your biology fights to hold, the food environment that does most of the eating for you, and where GLP-1 medications actually work. Along the way — why diets regain after you white-knuckle them, what The Biggest Loser six-year data show about resting metabolism, and four willpower myths worth retiring.

Hosted by Dr. Jordan Feigenbaum and Dr. Austin Baraki, co-founders of Barbell Medicine.

Timestamps

00:00 Cold open: Danny Cahill and The Biggest Loser01:03 What we mean by "willpower"05:48 Obesity tripled in ~60 years: the one number06:31 Adoption and twin studies: genes vs. household09:37 Set point vs. the defended range10:37 Gene–environment mismatch14:03 In the clinic: a lifelong weight history19:18 Losing weight vs. keeping it off20:26 Appetite doesn't reset (Sumithran)25:52 Metabolic adaptation and the Biggest Loser data34:07 Part 2: eating on autopilot35:10 Portion size runs the meal39:12 What changed in the food supply40:42 Same genes, new environment: Pima and immigrants43:20 Why ultra-processed food is easy to overeat50:28 Processing vs. calories: the Hall ward study52:36 When the brain changes eating: gourmand syndrome1:00:01 Why the willpower story stuck1:01:08 Taft, Churchill, and the intelligence myth1:02:43 Does intelligence predict weight? (sibling study)1:11:16 Are GLP-1s cheating? What they actually do1:15:10 Beyond the scale: muscle, health, nutrition1:24:21 Myth-busting: lightning round1:39:04 Three takeaways: what to actually do1:41:00 Danny Cahill, revisited Resources

Barbell Medicine coaching and templates: https://www.barbellmedicine.com

https://www.barbellmedicine.com/shop/subscriptions/plus-podcast-subscription/

https://www.barbellmedicine.com/shop/subscriptions/barbell-medicine-premium/

Signal book pre-order: https://www.barbellmedicine.com/shop/learning/signal/

Coaching, programs & templates: https://www.barbellmedicine.com/

Prevalence of Overweight, Obesity, and Severe Obesity Among Adults Age 20 and Older: United States, 1960-1962 Through August 2021-August 2023. NCHS Health E-Stats. 2024. https://www.cdc.gov/nchs/data/hestat/hestat111.htm

Obesity and Severe Obesity Prevalence in Adults: United States, August 2021-August 202