Research

Hormonal

Roux-en-Y gastric bypass surgery reduces long-term dietary fat intake and preference for high-fat foods in humans and rats, likely mediated by conditioned taste aversion and elevated postprandial GLP-1 levels.

For patients undergoing gastric bypass, the surgery not only restricts stomach size but also biologically reduces the desire for high-fat foods. This is driven by increased gut hormones (GLP-1, PYY) and conditioned taste aversion, where high-fat meals may cause mild discomfort, leading to a natural shift toward lower-fat diets. This physiological shift supports long-term weight maintenance.

GoodSupportsHIGH confidence
Proportion of dietary fat in gastric bypass patients was significantly lower 6 yr after surgery compared with patients after vertical-banded gastroplasty... Gastric bypass reduced total fat and caloric intake... and increased standard low-fat chow consumption compared with sham controls... Gastric bypass rats displayed much lower preferences for Intralipid concentrations > 0.5%... These findings suggest that changes in fat preference may contribute to long-term maintained weight loss after gastric bypass.
Carel W. le Roux et al. · American Journal of Physiology-Regulatory, Integrative and Comparative Physiology · 2011

Why this rating

Combines a randomized controlled trial in humans (n=16) with multiple controlled animal experiments, providing strong convergent evidence.

Source

Gastric bypass reduces fat intake and preference

Carel W. le Roux et al. · American Journal of Physiology-Regulatory, Integrative and Comparative Physiology · 2011

DOI 10.1152/ajpregu.00139.2011

rct · n=54Cited 240×
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DOI resolved against Crossref · corpus check 2026-06-10

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