Body composition after 'very-little-stomach' biliopancreatic bypass.

The nutritional status prior to and 3 months and 1 year after biliopancreatic bypass surgery was evaluated. The common nutritional indexes (serum albumin and transferin concentrations, daily urinary creatinine excretion and delayed hypersensitivity) were determined. The body compartments were derived from total body water (TBW) and total body sodium (TBNa), measured by dilutional technique, and total body potassium (TBK), calculated from TBW, TBNa, and the ratio of the sodium plus potassium content divided by the water content in a sample of whole blood. Before surgery, obese patients showed a dilatation of both fat an lean compartments with a normal lean body mass (LBM) qualitative composition, as indicated by TBNa/TBW, and TBNa/TBK ratios not greater than those measured in controls. Three months following very-little-stomach biliopancreatic bypass (VLS BPB), a consistent reduction of body weight and body fat were observed. The body cell mass value fell and reached a level closely similar to that found in lean control subjects. LBM showed only a slight decrease. A sharp increase of TBNa/TBW and TBNa/TBK ratios demonstrated a dilatation of the extracellular space. This malnutritional status was not detected by the usual nutritional parameters. One year after VLS BPB surgery, the patients' body composition became very similar to that of lean subjects, though a TBNa greater than that of controls suggested that a slightly expanded extracellular space was still present.