1. Weight loss in adult male Wistar rats by Roux-en-Y gastric bypass is primarily explained by caloric intake reduction and presurgery body weight.
- Author
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Hoornenborg CW, Somogyi E, Bruggink JE, Boyle CN, Lutz TA, Emous M, van Beek AP, Nyakas C, and van Dijk G
- Subjects
- Animals, Male, Rats, Energy Metabolism, Diet, High-Fat, Body Weight, Obesity physiopathology, Obesity surgery, Obesity metabolism, Caloric Restriction, Gastric Bypass, Weight Loss, Energy Intake, Rats, Wistar
- Abstract
Diets varying in macronutrient composition, energy density, and/or palatability may cause differences in outcome of bariatric surgery. In the present study, rats feeding a healthy low-fat (LF) diet or an obesogenic high-fat/sucrose diet (HF/S) were either subjected to Roux-en-Y gastric bypass surgery (RYGB) or sham surgery, and weight loss trajectories and various energy balance parameters were assessed. Before RYGB, rats eating an HF/S ( n = 14) diet increased body weight relative to rats eating an LF diet ( n = 20; P < 0.01). After RYGB, absolute weight loss was larger in HF/S ( n = 6) relative to LF feeding ( n = 6) rats, and this was associated with reduced cumulative energy intake (EI; P < 0.05) and increased locomotor activity (LA; P < 0.05-0.001), finally leading to similar levels of reduced body fat content in HF/S and LF rats 3 wk after surgery. Regression analysis revealed that variation in RYGB-induced body weight loss was best explained by models including 1 ) postoperative cumulative EI and preoperative body weight ( R
2 = 0.87) and 2 ) postoperative cumulative EI and diet ( R2 = 0.79), each without significant contribution of LA. Particularly rats on the LF diet became transiently more hypothermic and circadianally arrhythmic following RYGB (i.e., indicators of surgery-associated malaise) than HF/S feeding rats. Our data suggest that relative to feeding an LF diet, continued feeding an HF/S diet does not negatively impact recovery from RYGB surgery, yet it promotes RYGB-induced weight loss. The RYGB-induced weight loss is primarily explained by reduced cumulative EI and higher preoperative body weight, leading to comparably low levels of body fat content in HF/S and LF feeding rats. NEW & NOTEWORTHY Relative to feeding an LF diet, continued feeding an HF/S diet does not negatively impact recovery from RYGB surgery in rats. Relative to feeding an LF diet, continued feeding an HF/S diet promotes RYGB-induced weight loss. The RYGB-induced weight loss is primarily explained by reduced cumulative EI and higher preoperative body weight, leading to comparably low levels of body fat content in HF/S and LF feeding rats.- Published
- 2024
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