Energy Metabolic Adaptation and Cardiometabolic Improvements One Year After Gastric Bypass, Sleeve Gastrectomy, and Gastric Band

Context: It is not known whether the magnitude of metabolic adaptation, a greater than expected drop in energy expenditure, depends on the type of bariatric surgery and is associated with cardiometabolic improvements.

Objective: To compare changes in energy expenditure (metabolic chamber) and circulating cardiometabolic markers 8 weeks and 1 year after Roux-en-y bypass (RYGB), sleeve gastrectomy (SG), laparoscopic adjustable gastric band (LAGB), or a low-calorie diet (LCD). Design, Setting, Participants, and Intervention: This was a parallel-arm, prospective observational study of 30 individuals (27 females; mean age, 46 ± 2 years; body mass index, 47.2 ± 1.5 kg/m) either self-selecting bariatric surgery (five RYGB, nine SG, seven LAGB) or on a LCD (n = 9) intervention (800 kcal/d for 8 weeks, followed by weight maintenance).

Results: After 1 year, the RYGB and SG groups had similar degrees of body weight loss (33-36%), whereas the LAGB and LCD groups had 16 and 4% weight loss, respectively. After adjusting for changes in body composition, 24-hour energy expenditure was significantly decreased in all treatment groups at 8 weeks (-254 to -82 kcal/d), a drop that only persisted in RYGB (-124 ± 42 kcal/d; P = .002) and SG (-155 ± 118 kcal/d; P = .02) groups at 1 year. The degree of metabolic adaptation (24-hour and sleeping energy expenditure) was not significantly different between the treatment groups at either time-point. Plasma high-density lipoprotein and total and high molecular weight adiponectin were increased, and triglycerides and high-sensitivity C-reactive protein levels were reduced 1 year after RYGB or SG.

Conclusions: Metabolic adaptation of approximately 150 kcal/d occurs after RYGB and SG surgery. Future studies are required to examine whether these effects remain beyond 1 year.