Abstract
Background: Metabolic dysfunction-associated steatotic liver disease (MASLD) is increasingly prevalent among adolescents, especially those with obesity. It is the leading cause of liver-related morbidity and mortality and can progress to metabolic dysfunction-associated steatohepatitis, and eventually irreversible cirrhosis. There is currently no medical treatment recommended for MASLD in adolescents. Nutritional interventions, such as polyphenol supplementation, could be a non-pharmacological option to improve metabolic outcomes. Objectives: This pilot study aimed to preliminarily assess the impact of a 60-day polyphenol supplementation on measured resting energy expenditure (mREE) by indirect calorimetry (IC) in adolescents with MASLD. It also compared mREE by IC with predicted resting energy expenditure (pREE) using the WHO and Schofield formulae. Methods: This single-blind randomized controlled trial enrolled 23 adolescents with MASLD, of which 11 completed IC assessments before and after the 60-day polyphenol supplementation (intervention group, n = 5) or no supplementation (controls, n = 6). There was no placebo. Caloric intake was assessed to evaluate its impact on mREE and mREE was compared to pREE using the WHO and Schofield equations. Results: Participants in the intervention group had a statistically significant increase in mREE between the two visits (+89.6 kcal/day, p = 0.037), while no difference was found in the control group. When compared to the control group, the intervention group had a greater variation in mREE between visits (+100.4 kcal/day, p = 0.021). No significant changes were observed when adjusting mREE for body weight. Also, there were no significant changes in body weight in the two groups between the visits. Both the WHO and Schofield equations overestimated pREE with an average percentage of pREE of 88.8% and 91.0%, respectively. Conclusions: Although several methodological limitations prevent clear conclusions from being drawn at this stage, this study suggests that polyphenol supplementation could increase REE in adolescents with MASLD and that the WHO and Schofield equations tend to overestimate REE in obese patients.