The effect of protein supplements on weight loss, body composition, protein status, and micronutrients post laparoscopic sleeve gastrectomy (LSG): A Randomised Controlled Trial (RCT)

Ann Med Surg (Lond). 2022 Jan 1:74:103220. doi: 10.1016/j.amsu.2021.103220. eCollection 2022 Feb.


Background: Low protein intake post-bariatric surgery can result in protein malnutrition, and muscle mass loss. Authors aim to assess the effect of protein supplements on weight loss, body composition, and micronutrient status following LSG.

Methods: This is a double-blinded RCT conducted between February/2017 to January/2018. Eligible post LSG patients were randomized into the intervention group who received daily protein supplements containing 20 g of protein and placebo group received zero protein supplements. Both groups received a standardized diet. Weight loss, body composition, and micronutrient status were analyzed at 1, 3, and 6 months.

Results: 48 participants were included in the final analysis (intervention: 21 and placebo:27). Excess weight loss percentage (EWL%) at 6 months was comparable between both groups (69.44 ± 21.99% and 71.40 ± 19.27% respectively). No significant difference observed in the anthropometric parameters. There was an increase in muscle mass and a decrease in muscle mass loss in the intervention group throughout the study period. However, these changes were not statistically significant. There was a significant increase in total protein (P=0.027) and magnesium (P=0.008) in the intervention group at 3 months. Albumin and iron levels were significantly higher at 6 months in the intervention group (P=0.036 & P=0.028 respectively). Other micronutrients did not differ at any time point between both groups.

Conclusion: Protein supplements resulted in significant improvement in total protein, albumin, magnesium, and iron levels post LSG. Although not significant, protein supplements helped in maintaining the muscle mass and preventing muscle mass loss.

Original article: This RCT is an original article and provides a level 2 evidence.

Keywords: Body composition; Fat mass; Laparoscopic sleeve gastrectomy; Micronutrients deficiency; Muscle mass; Protein deficiency; Protein supplement.