Marc Bates, MPH, a leading metabolic health coach, has released a comprehensive YouTube video challenging the traditional "calories in, calories out" (CICO) weight management model. The video exposes how this widely accepted approach fundamentally misunderstands human metabolism by treating the body as a mechanical system rather than a complex biological organism.

Bates argues that the CICO model's foundation on bomb calorimeter measurements ignores critical hormonal and enzymatic pathways that govern human metabolism. His investigation reveals why clients meticulously counting calories and exercising religiously still gain fat or fail to lose weight.

"You're still thinking like a physicist. But the human body is a biochemical organism, not a bomb calorimeter," Bates states in the video, addressing nutritionists who dismiss hormonal influences on weight management.

The video demonstrates how insulin acts as a metabolic gatekeeper, determining whether calories are stored as fat or burned for energy. Bates explains that someone eating 1,200 calories can remain trapped in fat storage mode if insulin levels stay elevated, while another person consuming 2,000 calories of protein and fat may lose weight rapidly.

Central to Bates' argument is the role of Hormone-Sensitive Lipase (HSL), an enzyme that breaks down stored fat. Insulin powerfully inhibits HSL, preventing fat mobilization even during caloric restriction. This biochemical reality explains why traditional calorie counting fails millions of dieters.

"It's not just about how many calories go in. It's about how many calories your body is allowed to burn," Bates emphasizes, proposing a more accurate thermodynamic model that accounts for hormonal regulation of energy partitioning.

The video positions food as information rather than mere fuel, reframing weight management from simple arithmetic to understanding how hormones, metabolic history, and food quality determine caloric fate in the human body.