Effects of Diet versus Gastric Bypass on Metabolic Function in Diabetes

This study compared the metabolic effects of Roux-en-Y gastric bypass surgery and diet therapy in patients with obesity and type 2 diabetes, focusing on changes independent of weight loss. Twenty two participants were evaluated before and after matched (18%) weight loss induced by either gastric bypass (surgery group) or a low calorie diet (diet group). The primary outcome was hepatic insulin sensitivity, assessed via a hyperinsulinemic euglycemic clamp. Results showed significant improvements in hepatic insulin sensitivity, muscle insulin sensitivity, beta cell function, and 24-hour plasma glucose and insulin profiles in both groups, with no clinically important differences between the interventions. Weight loss itself, rather than the method (surgery or diet), was the primary driver of metabolic benefits. Hyperkalemia related adverse events were rare, and no major complications occurred. The study concludes that gastric bypass does not confer unique metabolic advantages beyond those achieved through equivalent weight loss via diet.

This study compared the metabolic effects of Roux-en-Y gastric bypass surgery and diet therapy in patients with obesity and type 2 diabetes, focusing on changes independent of weight loss. Twenty two participants were evaluated before and after matched (18%) weight loss induced by either gastric bypass (surgery group) or a low calorie diet (diet group). The primary outcome was hepatic insulin sensitivity, assessed via a hyperinsulinemic euglycemic clamp. Results showed significant improvements in hepatic insulin sensitivity, muscle insulin sensitivity, beta cell function, and 24-hour plasma glucose and insulin profiles in both groups, with no clinically important differences between the interventions. Weight loss itself, rather than the method (surgery or diet), was the primary driver of metabolic benefits. Hyperkalemia related adverse events were rare, and no major complications occurred. The study concludes that gastric bypass does not confer unique metabolic advantages beyond those achieved through equivalent weight loss via diet.