Which mechanistic explanation best analyzes how set point theory and physiological adaptations after weight loss contribute to weight regain?

Physiological adaptations after weight loss exclusively improve insulin sensitivity and therefore lead to spontaneous long-term weight maintenance without behavioral support.

Set point theory states that only psychological factors cause regain; physiological energy expenditure and appetite hormones remain unchanged after weight loss.

After weight loss, resting energy expenditure often decreases and appetite-regulating hormones (e.g., ghrelin) may increase, creating stronger physiological drives to eat while burning fewer calories—consistent with set point adaptations favoring regain.

After weight loss, the body always increases basal metabolic rate and permanently suppresses appetite, which directly prevents any meaningful risk of weight regain.