Satiety signaling
The body's fullness signals (leptin, PYY, GLP-1) that tell the brain to stop eating.
Satiety signaling is the network of hormones and nerves that communicate fullness, including leptin from fat tissue, peptide YY (PYY) and GLP-1 from the gut, and stretch signals from the stomach. GLP-1 medications boost this signaling artificially. After stopping, satiety signals weaken (PYY drops, the GLP-1 boost is gone) while hunger signals rise, an asymmetry that defends the old, higher weight. Foods high in protein, fiber, and water support natural satiety signaling.