title: Roux-en-Y gastric bypass in rats progressively decreases the proportion of fat calories selected from a palatable cafeteria diet.
abstract: Roux-en-Y gastric bypass surgery (RYGB) decreases caloric intake in both human patients and rodent models. In long-term intake tests, rats decrease their preference for fat and/or sugar after RYGB, and patients may have similar changes in food selection. Here we evaluated the impact of RYGB on intake during a "cafeteria"-style presentation of foods to assess if rats would lower the percentage of calories taken from fat and/or sugar after RYGB in a more complex dietary context. Male Sprague-Dawley rats that underwent either RYGB or sham surgery (Sham) were presurgically and postsurgically given 8-days free access to four semisolid foods representative of different fat and sugar levels along with standard chow and water. Compared with Sham rats, RYGB rats took proportionally fewer calories from fat and more calories from carbohydrates; the latter was not attributable to an increase in sugar intake. The proportion of calories taken from protein after RYGB also increased slightly. Importantly, these postsurgical macronutrient caloric intake changes in the RYGB rats were progressive, making it unlikely that the surgery had an immediate impact on the hedonic evaluation of the foods and strongly suggesting that learning is influencing the food choices. Indeed, despite these dietary shifts, RYGB, as well as Sham, rats continued to select the majority of their calories from the high-fat/high-sugar option. Apparently after RYGB, rats can progressively regulate their intake and selection of complex foods to achieve a seemingly healthier macronutrient dietary composition.
authors: Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida;
authors: Clare M
authors: CM
authors: Mathes
authors: Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida;
authors: Chanel
authors: C
authors: Letourneau
authors: Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida;
authors: Ginger D
authors: GD
authors: Blonde
authors: Diabetes Complications Research Centre, School of Medicine and Medical Science, University College Dublin, Dublin, Ireland; Investigative Medicine, Imperial College London, London, United Kingdom; and Gastrosurgical Laboratory, University of Gothenburg, Gothenburg, Sweden.
authors: Carel W
authors: CW
authors: le Roux
authors: Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida; spector@psy.fsu.edu.
authors: Alan C
authors: AC
authors: Spector
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D001070:Appetitive Behavior; D004032:Diet; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D002149:Energy Intake; D015390:Gastric Bypass; D008297:Male; D051381:Rats
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins
keywords: bariatric surgery; conditioned avoidance; diet-induced obesity; supermarket diet