Effect of Plant vs Animal Protein Supplementation on Body Composition in Youth Soccer Players

This prospective, single-blind, randomized controlled trial investigates the comparative effects of plant-based protein (soy and rice blend) versus animal-based protein (whey) supplementation on body composition parameters in elite male youth soccer players. Twenty-five players (ages 16-18.7 years) from Udinese Calcio's Primavera (U-19) category are randomized into three groups: Plant Protein Group (n=8), Animal Protein Group (n=9), and Placebo Group (n=8). The intervention consists of post-training protein supplementation (17g protein/dose) administered within 15-30 minutes after each training session over a 4-week microcycle during the competitive season. Body composition is assessed using a multi-compartmental model including anthropometry (ISAK protocol), bioelectrical impedance analysis (BIA), and dual-energy X-ray absorptiometry (DEXA).