Your body defends a particular weight with surprising persistence. Research by Leibel and Rosenbaum shows that when you lose weight, metabolic rate drops, hunger hormones increase, and energy expenditure decreases—all pushing you back toward previous weight. The “Biggest Loser” study found persistent metabolic suppression years later. You’re not fighting just habits; you’re fighting physiology.
This companion covers evidence for set point, defense mechanisms, evolutionary reasons, whether it can change, and working with your biology. (5 min read)