Direct measurement of macronutrient intake and preference 1 year after Roux-en-Y gastric bypass (RYGB)

Introduction: Patients report food preference changes away from sweet and fatty foods after Roux‐en‐Y gastric bypass (RYGB). Verbal report is however unreliable. Direct measurement of food intake and preference in humans after RYGB are needed for the phenomenon. Objectives: 1) To conduct a longitudinal self‐selection buffet paradigm study coupled to direct assessment of food preferences after RYGB 2) Test blockade of postprandial gut hormone responses. Methods: An interim analysis was performedonRYGB (n=6) and normal weight subjects (n=4). Caloric and macronutrient intake was assessed; 1 month before, 3 and 12 months after surgery. At 12 months, subjects were randomised to receive saline or octreotide to block gut hormone responses in a crossover design. Results: In healthy volunteers, calorie intake and food preferences remained stable. In RYGB subjects calorie intake decreased by 47% vs baseline (1949±257 to 1039±101kcal, p=0.02). Percentage total carbohydrates preference was 49.1±5.2% pre and 34.2±2.9% 1 year after RYGB, p=0.05; of which sugars were 22.4±3.7% pre and 13.5±2.4% 1 year after, p=0.87; other carbohydrates were 26.7±3.5% pre and 20.7±2.2% 1 year after, p=0.10; fat was 38.3±5.2% pre and 50.4±3.1% 1 year after, p=0.49 and protein was 11.8±0.5% pre and 14.6±1.8% 1 year after, p=0.23. Octreotide had no effect on calorie intake in either group. In RYGB subjects on the Octreotide day, total carbohydrate intake was increased by 9.9±1.7%, p=0.001 and fat intake decreased by 3.5±1.3%, p=0.04 versus saline day. No change were observed in protein, sugar or other carbohydrate preferences. Conclusion: Direct measurement of calorie intake and macronutrient preferences is feasible in humans. Interim results suggest a reduction in total calories and preference for total carbohydrates one year after RYGB. In the context of a buffet meal octreotide did not increase calorie intake. Reanalysis is required once larger numbers of patients complete the assessments.