Applied nutritional investigationImpact of protein supplementation after bariatric surgery: A randomized controlled double-blind pilot study

- Protein supplementation after bariatric surgery leads to increased loss of body fat mass within six mo.
- Protein supplementation after bariatric surgery leads to decreased loss of lean body mass within six mo.
- Protein supplementation after bariatric surgery supports reaching the recommended goals regarding protein intake.
- Protein supplementation after bariatric surgery does not deteriorate markers of renal function.

ObjectivesBariatric patients are at risk of protein deficiency. The aim of this study was to determine possible benefits of postoperative protein supplementation weight reduction, body composition, and protein status.MethodsTwenty obese patients who underwent bariatric surgery were randomized either to the protein (PRO) group, which received a daily protein supplement over 6 months postoperatively, or to the control (CON) group, which received an isocaloric placebo in a double-blind fashion. Data on protein and energy intake, body weight, body composition, blood proteins, and grip force was collected preinterventionally and at 1, 3, and 6 months postoperatively.ResultsIn both groups body weight was significantly reduced to a similar extent (after 6 months: PRO group 25.4 ± 7.2%, CON group 20.9 ± 3.9%; intergroup comparison P > 0.05). Protein intake was steadily increased in the PRO group, but not in the CON group, and reached maximum at month 6 (25.4 ± 3.7% of energy intake versus 15.8 ± 4.4%; P < 0.001). In the PRO group, body fat mass loss was higher than that in the CON group (79% of absolute weight loss versus 73%; P = 0.02) while lean body mass loss was less pronounced (21% versus 27%, P = 0.05). Blood proteins and grip force did not differ at any time point between the two groups.ConclusionsThe present study suggests that protein supplementation after bariatric surgery improves body composition by enhancing loss of body fat mass and reducing loss of lean body mass within the 6 months follow up.