Comparison of Protein- or Amino Acid-Based Supplements in the Rehabilitation of Men with Severe Obesity: A Randomized Controlled Pilot Study

Background: Weight loss is associated with a reduction in all body compartments, including muscle mass (MM), and this effect produces a decrease in function and muscle strength. Our objective was to assess the impact of protein or amino acid supplements on MM loss in middle-aged men (age < 65 years) with severe obesity (BMI > 35 kg/m(2)) during weight loss. Materials and Methods: We conducted a single-site randomized controlled trial (Clinicaltrials.gov NCT05143398) with 40 in-patient male subjects with severe obesity. Participants underwent an intervention program consisting of a low-calorie balanced diet and structured physical activity. They were randomly assigned to 4-week treatment groups: (1) control (CTR, N = 10), (2) protein (P, N = 10), (3) branched-chain amino acid (BCAA, N = 10), and (4) essential amino acid mixture with tricarboxylic acid cycle intermediates (PD-E07, N = 10) supplementation. Results: Following 4 weeks of intervention, all groups showed similar reductions in body weight compared to baseline. When examining the delta values, a notable increase in muscle mass (MM) was observed in the PD-E07 intervention group [MM (kg): 2.84 & PLUSMN; 3.57; MM (%): 3.63 & PLUSMN; 3.14], in contrast to the CTR group [MM (kg): -2.46 & PLUSMN; 3.04; MM (%): -0.47 & PLUSMN; 2.28], with a statistical significance of p = 0.045 and p = 0.023, respectively. However, the MM values for the P group [MM (kg): -2.75 & PLUSMN; 5.98, p = 0.734; MM (%): -0.44 & PLUSMN; 4.02, p = 0.990] and the BCAA group [MM (kg): -1 & PLUSMN; 3.3, p = 0.734; MM (%): 0.34 & PLUSMN; 2.85, p = 0.956] did not exhibit a statistically significant difference when compared to the CTR group. Conclusions: Amino acid-based supplements may effectively mitigate the loss of MM typically observed during weight reduction. Further validation through large-scale studies is necessary.

Automated summary

This study aimed to assess the impact of protein or amino acid supplements on muscle mass loss in middle-aged men. The results showed that the PD-E07 supplement group had a notable increase in muscle mass compared to the control group, while the protein and BCAA supplement groups did not exhibit a significant difference. Therefore, amino acid-based supplements may effectively mitigate the loss of muscle mass during weight reduction.