Effect on Body Composition of Protein Supplementation During the First Six Months After Bariatric Surgery

Introduction: Progressive diets after metabolic and bariatric surgery that are restricted in protein, protein intolerance, and malabsorption from techniques that exclude the duodenum result in nearly half of patients not consuming the recommended protein intake after surgery. Methods A cohort study was designed with 181 patients who underwent sleeve gastrectomy, gastric bypass, and biliopancreatic diversion. Eighty-eight patients (prospective cohort) received a progressive diet with a normocaloric, high-protein oral nutritional supplement during the first two weeks after surgery (817 kcal, 65.7 g protein/day). A historical cohort of 93 patients treated with a standard progressive diet (217 kcal, 11.7 g protein/day). Anthropometric and body composition data were analyzed before surgery, and at 1 and 6 months post-surgery. Results percentage of weight loss was observed in patients on the low-protein diet (LPD) at one month (LPD 13.44% (6.71%) vs. high-protein diet (HPD) 10.78% (4.45%); p < 0.01) and at six months (LPD 22.89% (8.78%) vs.HPD 19.49% (7.01%); p < 0.01). There was maintenance of lean mass index (LPD − 1.37 (0.69) kg vs.HPD + 0.31 (0.79) kg; p = 0.01) in HPD patients at one month, with no differences in fat mass loss. At six months, there was less loss of lean mass index (LPD − 2.75 (2.01) kg vs.HPD − 1.24 (2.06) kg; p = 0.00) and phase angle (LPD − 1.25 (51.77) kg vs. HPD + 0.83 (0.12) kg; p = 0.01) in HPD patients. Conclusions Patients on HPD showed maintenance of lean mass index and phase angle compared to those on LPD during the first six months after bariatric surgery.