title: Gastric bypass reduces fat intake and preference.
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.
authors: Dept. of Investigative Medicine, Hammersmith Hospital, Imperial College London, Du Cane Road, London W12 0NN, UK. c.leroux@imperial.ac.uk
authors: Carel W
authors: CW
authors: le Roux
authors: Marco
authors: M
authors: Bueter
authors: Nadine
authors: N
authors: Theis
authors: Malin
authors: M
authors: Werling
authors: Hutan
authors: H
authors: Ashrafian
authors: Christian
authors: C
authors: Löwenstein
authors: Thanos
authors: T
authors: Athanasiou
authors: Stephen R
authors: SR
authors: Bloom
authors: Alan C
authors: AC
authors: Spector
authors: Torsten
authors: T
authors: Olbers
authors: Thomas A
authors: TA
authors: Lutz
mesh_terms: D000818:Animals; D004041:Dietary Fats / Q000378:metabolism*; D004435:Eating / Q000502:physiology*; D002149:Energy Intake / Q000502:physiology; D005260:Female; D005518:Food Preferences / Q000502:physiology*; D015390:Gastric Bypass; D015391:Gastroplasty; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism; D006801:Humans; D008297:Male; D023421:Models, Animal; D009765:Obesity / Q000601:surgery*; D051381:Rats; D017208:Rats, Wistar; D012439:Saccharin / Q000378:metabolism; D013649:Taste / Q000502:physiology; D013997:Time Factors
chemical_list: D004041:Dietary Fats; D052216:Glucagon-Like Peptide 1; D012439:Saccharin