High-Protein Plant-Based Diet Versus a Protein-Matched Omnivorous Diet to Support Resistance Training Adaptations: A Comparison Between Habitual Vegans and Omnivores

Author(s)

Hevia-Larrain, Victoria ^[1] ; Gualano, Bruno ^{[1, 2]} ; Longobardi, Igor ^[1] ; Gil, Saulo ^[1] ; Fernandes, Alan L. ^[1] ; Costa, Luiz A. R. ^[1] ; Pereira, Rosa M. R. ^[3] ; Artioli, Guilherme G. ^[1] ; Phillips, Stuart M. ^[4] ; Roschel, Hamilton ^[1]

Affiliation

^[1] Univ Sao Paulo, Appl Physiol & Nutr Res Grp, Sch Phys Educ & Sport, Rheumatol Div, Fac Med FMUSP, Ave Prof Mello Moraes 65, BR-05508030 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Food Res Ctr, R Lago 250, Sao Paulo, SP - Brazil

^[3] Univ Sao Paulo, Div Rheumatol, Fac Med FMUSP, Bone Metab Lab, Ave Doutor Arnaldo 455, Sao Paulo, SP - Brazil

^[4] McMaster Univ, Dept Kinesiol, 1280 Main St West, Hamilton, ON - Canada

• Document type: Journal article
• Source: SPORTS MEDICINE; v. 51, n. 6 FEB 2021.
• Web of Science Citations: 2

Abstract

Background Acute protein turnover studies suggest lower anabolic response after ingestion of plant vs. animal proteins. However, the effects of an exclusively plant-based protein diet on resistance training-induced adaptations are under investigation. Objective To investigate the effects of dietary protein source {[}exclusively plant-based vs. mixed diet] on changes in muscle mass and strength in healthy young men undertaking resistance training. Methods Nineteen young men who were habitual vegans (VEG 26 +/- 5 years; 72.7 +/- 7.1 kg, 22.9 +/- 2.3 kg/m(2)) and nineteen young men who were omnivores (OMN 26 +/- 4 years; 73.3 +/- 7.8 kg, 23.6 +/- 2.3 kg/m(2)) undertook a 12-week, twice weekly, supervised resistance training program. Habitual protein intake was assessed at baseline and adjusted to 1.6 g kg(-1) day(-1) via supplemental protein (soy for VEG or whey for OMN). Dietary intake was monitored every four weeks during the intervention. Leg lean mass, whole muscle, and muscle fiber cross-sectional area (CSA), as well as leg-press 1RM were assessed before (PRE) and after the intervention (POST). Results Both groups showed significant (all p < 0.05) PRE-to-POST increases in leg lean mass (VEG: 1.2 +/- 1.0 kg; OMN: 1.2 +/- 0.8 kg), rectus femoris CSA (VEG: 1.0 +/- 0.6 cm(2); OMN: 0.9 +/- 0.5 cm(2)), vastus lateralis CSA (VEG: 2.2 +/- 1.1 cm(2); OMN: 2.8 +/- 1.0 cm(2)), vastus lateralis muscle fiber type I (VEG: 741 +/- 323 mu m(2); OMN: 677 +/- 617 mu m(2)) and type II CSA (VEG: 921 +/- 458 mu m(2); OMN: 844 +/- 638 mu m(2)), and leg-press 1RM (VEG: 97 +/- 38 kg; OMN: 117 +/- 35 kg), with no between-group differences for any of the variables (all p > 0.05). Conclusion A high-protein (similar to 1.6 g kg(-1) day(-1)), exclusively plant-based diet (plant-based whole foods + soy protein isolate supplementation) is not different than a protein-matched mixed diet (mixed whole foods + whey protein supplementation) in supporting muscle strength and mass accrual, suggesting that protein source does not affect resistance training-induced adaptations in untrained young men consuming adequate amounts of protein. (AU)

• FAPESP's process: 16/22083-3 - The influence of the dietary protein source on long-term resistance training-induced changes
• Grantee: Victoria María de Los Ángeles Hevia Larraín
• Support Opportunities: Scholarships in Brazil - Master