Evaluating Protein Liquid Supplementation for Enhanced Protein Intake and Adherence at Short-Term After Metabolic and Bariatric Surgery: A Pilot Randomized Controlled Trial

Abstract

Background: The health benefits of metabolic and bariatric surgery (MBS) are associated with improvements in comorbidities and reduction in their incidence and mortality rates. Food restriction and anatomical changes result in a higher risk of nutritional complications and must be considered. This study aimed to evaluate the difference in adherence and daily protein intake between a protein liquid supplementation (PLS) versus a conventional protein powder (PPS) in patients undergoing (MBS). Methods: A 2-month parallel, randomized, controlled trial including 50 patients (PLS n = 15; PPS n = 35) undergoing Roux-en-Y gastric bypass (GBP) was conducted. Body composition (bioimpedance analysis), resting energy expenditure (indirect calorimetry), and nutritional status (serum levels of macronutrients and micronutrients) were evaluated before pre- and post-operatively. Dietary protein intake and supplementation adherence were monitored every 15 days. Results: Weight loss and changes in fat-free mass were comparable between the two groups after GBP (PLS: − 12.9 ± 4.8 vs. PPS: − 14.5 ± 6.3) (p > 0.05), (PLS: − 12.5 ± 3.7 vs. PPS: − 11.2 ± 3.3) (p > 0.05), respectively. The PLS group showed a higher basal metabolic rate at 2 months (PLS: 1843.4 ± 278.3 vs. PPS: 1642.2 ± 249.8) (p < 0.05). Adherence to the PLS group (102.7 ± 77.2%) was higher than the PPS group (42.0 ± 23.7%) (p = 0.012). Prevalence of 25OH-vitamin D deficiency and abnormal transferrin saturation were (PLS: 28.6% vs. PPS: 90% p < 0.001), (PLS: 8.3% vs. PPS: 57.1% p = 0.037), respectively. Conclusions: A protein liquid supplementation appears to be an alternative in achieving the protein recommendations after GBP and may facilitate dietary adherence while reducing the incidence of nutritional deficiencies. This study is registered in ClinicalTrials.gov; no.[Blinded].