Resting Energy Expenditure in Long-Term Postobese Subjects after Weight Normalization by Dieting or Biliopancreatic Diversion.

Resting energy expenditure (REE) was measured by Indirect calorimetry in three groups of subjects closely matched for body weight (BW) and body composition. Five subjects had reduced from lO3 kg (129-90) to normal BW by dieting. Fourteen subjects had normalized their weight (preop 120 kg, from 168 to 100) following biliopancreatic diversion (BPD). All subjects in both groups had essentially maintained a stable weight for at least 2 years before the study. Ten healthy volunteers who had never been obese served as controls. No differences in REE were observed between post-BPD and control subjects, while lower (p < 0.05) values of REE were found in post-diet subjects. A long-lasting reduction of REE, in spite of a normal body composition, might partly account for the very poor long-term results of conventional dietary treatment. The unreduced REE following BPD may contribute, along with the permanent intestinal malabsorption, to the excellent long-term weight maintenance caused by this surgical procedure.