Obese individuals who lose the same amount of weight through bariatric surgery as through a low-calorie diet experience stronger feelings of fullness after meals, eat less in anticipation of future...
Mechanism
Synthesis from 1 study
After weight-loss surgery, food moves faster to the lower gut, making cells there release much more of a fullness hormone called GLP-1 (10.1007/s11695-025-08473-5). This hormone tells the brain you're full and reduces hunger, even if you've lost the same weight as someone on a diet...
Most probable mechanism
After metabolic and bariatric surgery, food moves faster through a reshaped gut and hits the lower intestine sooner, which causes cells there to release much more of a hormone called GLP-1 (10.1007/s11695-025-08473-5). This hormone travels to nerves in the gut and to the brain, telling the person they are full and reducing their desire to eat more, even when they’ve lost the same amount of weight as someone on a diet (10.1007/s11695-025-08473-5).
Surgical rearrangement of the gastrointestinal tract (e.g., gastric pouch creation and intestinal bypass in Roux-en-Y gastric bypass or gastric sleeve resection in sleeve gastrectomy) alters the speed and route of nutrient passage, accelerating delivery of ingested nutrients to the distal ileum (10.1007/s11695-025-08473-5).
Accelerated nutrient exposure to the distal ileum stimulates enteroendocrine L-cells to secrete significantly higher levels of glucagon-like peptide-1 (GLP-1) postprandially, with a two-fold increase observed after surgery compared to diet-induced weight loss (10.1007/s11695-025-08473-5).
Elevated postprandial GLP-1 binds to receptors on vagal afferent neurons and in the brainstem and hypothalamus, activating central satiety pathways that enhance the sensation of fullness and suppress the motivation to eat (10.1007/s11695-025-08473-5).
Activation of these central satiety pathways results in significantly increased postprandial fullness and reduced prospective eating, with GLP-1 levels strongly correlating with these behavioral changes (r = 0.69) (10.1007/s11695-025-08473-5).
Evidence from Studies
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