Gastric bypass reduces fat intake and preference

Am J Physiol Regul Integr Comp Physiol. 2011 Oct;301(4):R1057-66. doi: 10.1152/ajpregu.00139.2011. Epub 2011 Jul 6.

Abstract

Roux-en-Y gastric bypass is the most effective therapy for morbid obesity. This study investigated how gastric bypass affects intake of and preference for high-fat food in an experimental (rat) study and within a trial setting (human). Proportion of dietary fat in gastric bypass patients was significantly lower 6 yr after surgery compared with patients after vertical-banded gastroplasty (P = 0.046). Gastric bypass reduced total fat and caloric intake (P < 0.001) and increased standard low-fat chow consumption compared with sham controls (P < 0.001) in rats. Compared with sham-operated rats, gastric bypass rats displayed much lower preferences for Intralipid concentrations > 0.5% in an ascending concentration series (0.005%, 0.01%, 0.05%, 0.1%, 0.5%, 1%, 5%) of two-bottle preference tests (P = 0.005). This effect was demonstrated 10 and 200 days after surgery. However, there was no difference in appetitive or consummatory behavior in the brief access test between the two groups (P = 0.71) using similar Intralipid concentrations (0.005% through 5%). Levels of glucagon-like peptide-1 (GLP-1) were increased after gastric bypass as expected. An oral gavage of 1 ml corn oil after saccharin ingestion in gastric bypass rats induced a conditioned taste aversion. These findings suggest that changes in fat preference may contribute to long-term maintained weight loss after gastric bypass. Postingestive effects of high-fat nutrients resulting in conditioned taste aversion may partially explain this observation; the role of GLP-1 in mediating postprandial responses after gastric bypass requires further investigation.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dietary Fats / metabolism*
  • Eating / physiology*
  • Energy Intake / physiology
  • Female
  • Food Preferences / physiology*
  • Gastric Bypass*
  • Gastroplasty*
  • Glucagon-Like Peptide 1 / metabolism
  • Humans
  • Male
  • Models, Animal
  • Obesity / surgery*
  • Rats
  • Rats, Wistar
  • Saccharin / metabolism
  • Taste / physiology
  • Time Factors

Substances

  • Dietary Fats
  • Glucagon-Like Peptide 1
  • Saccharin