Effects of a (poly)phenol-rich supplement on body composition and cardiometabolic health in adults with severe obesity: a randomized controlled trial.

BACKGROUND AND AIMS: Evidence suggests that (poly)phenols may support obesity management; however, their potential benefits in severe obesity remain understudied. This study evaluated the effects of 12-week (poly)phenol supplementation alongside a hypocaloric diet on body weight and other obesity-related health outcomes in adults with severe obesity. METHODS AND RESULTS: In this double-blind, placebo-controlled randomized clinical trial, 37 adults with severe obesity recruited at Bellvitge University Hospital (Barcelona, Spain) were randomly assigned to receive either a (poly)phenol-rich supplement or a placebo, alongside a hypocaloric diet (∼1200 kcal/day) for 12 weeks. The primary outcome was body weight; secondary outcomes included body composition, and cardiometabolic and inflammatory biomarkers. Longitudinal changes were analyzed using baseline-adjusted linear mixed-effects models. 36 participants were included in the main analysis, of whom 34 completed the intervention. The control and the supplement group achieved similar improvements in body weight, body composition, and most cardiometabolic and inflammatory biomarkers. However, fasting glucose showed a significant between-group difference (-7.51 [-14.39, -0.63] mg/dL) and a significant group × time interaction (p = 0.026), largely driven by an increase in the control group. Triglyceride concentrations also differed significantly between groups (-30.80 [-60.79, -0.81] mg/dL), although the group × time interaction was not significant (p = 0.169). CONCLUSION: In adults with severe obesity, 12-week supplementation with (poly)phenol-rich extracts did not provide additional benefits on body weight or body composition outcomes beyond dietary intervention alone but may have helped preserve a more favorable cardiometabolic profile. Larger and longer trials are needed to confirm these findings. REGISTRATION NUMBER: NCT05428540.