Body composition in morbidly obese patients before and after jejunoileal bypass.

A clinical and body compositional study has been made of 150 patients with morbid obesity and their responses to four different dimensional alterations of jejunoileal bypass. Total body potassium was estimated by measuring 40K with the whole body counter and total body water by tritiated water dilution. Body compositional data derived from these measurements were compared in the 4 groups during followup periods up to 4 years and related to clinical results. Initially, patients were two or more times overweight due to excess (60 to 65%) body fat and increased hydration (21%) of lean tissues. The 80 end-to-end jejunoileal bypass procedures of Groups 3 and 4 (30 cm jejunum to 15 or 20 cm ileum) had better weight losses and clinical results in followup were rated "good" in 60% and 81% respectively. These results were accompanied by a greater degree of improvement in body composition than was observed in the other groups under study.