Comparison of the effect of soya protein and whey protein on body composition: a meta-analysis of randomised clinical trials

• Published in: British journal of nutrition Vol. 127; no. 6; pp. 885 - 895
• Main Authors: Piri Damaghi, Masoome, Mirzababaei, Atieh, Moradi, Sajjad, Daneshzad, Elnaz, Tavakoli, Atefeh, Clark, Cain C.T., Mirzaei, Khadijeh
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 28.03.2022
• Subjects: Abdomen; Adult; Adults; Amino acids; Amino Acids, Essential; Bias; Body Composition; Body fat; Body mass; Body mass index; Clinical trials; Collaboration; Dietary Supplements; Heterogeneity; Human and Clinical Nutrition; Humans; Lean body mass; Meta-analysis; Muscles; Obesity; Overweight; Parameters; Protein biosynthesis; Protein composition; Protein synthesis; Proteins; Randomized Controlled Trials as Topic; Search engines; Soybean Proteins - pharmacology; Standard deviation; Strength training; Subgroups; Supplements; Synthesis; Weight control; Whey; Whey protein; Whey Proteins - pharmacology; Body fat percentage; Body mass; Soya protein; Lean body mass; Whey protein; Fat mass; Body composition
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1017/S0007114521001550

Essential amino acids (EAA) promote the process of regulating muscle synthesis. Thus, whey protein that contains higher amounts of EAA can have a considerable effect on modifying muscle synthesis. However, there is insufficient evidence regarding the effect of soya and whey protein supplementation on body composition. Thus, we sought to perform a meta-analysis of published randomised clinical trials that examined the effect of whey protein supplementation and soya protein supplementation on body composition (lean body mass, fat mass, body mass and body fat percentage) in adults. We searched PubMed, Scopus and Google Scholar, up to August 2020, for all relevant published articles assessing soya protein supplementation and whey protein supplementation on body composition parameters. We included all randomised clinical trials that investigated the effect of whey protein supplementation and soya protein supplementation on body composition in adults. Pooled means and standard deviations were calculated using random effects models. Subgroup analysis was applied to discern possible sources of heterogeneity. After excluding non-relevant articles, ten studies, with 596 participants, remained in this study. We found a significant increase in lean body mass after whey protein supplementation (weighted mean difference (WMD: 0·91; 95 % CI 0·15, 1·67; P = 0·019). We observed no significant change between whey protein supplementation and body mass, fat mass and body fat percentage. We found no significant change between soya protein supplementation and body composition parameters. Whey protein supplementation significantly improved body composition via increases in lean body mass, without influencing fat mass, body mass and body fat percentage.