Data published in Sports Medicine showed that a plant-based diet composed of plant-based whole foods and soy protein isolate supplementation was as efficacious an omnivorous diet composed of mixed whole foods and whey protein supplementation for supporting muscle building and strength.
“This suggests that dietary protein source does not affect resistance training-induced adaptations in untrained young men, provided adequate amounts of protein are consumed,” wrote the researchers, led by Hamilton Roschel, PhD, from the Applied Physiology & Nutrition Research Group at the University of Sao Paulo, Brazil.
The study was funded by the Research Support Foundation of the State of São Paulo (FAPESP).
IFF: It give us a little different message about this specific population
The study’s findings were welcomed by Barbara Peters, nutrition scientist, IFF, which supplied the soy protein isolate used in the study (formerly DuPont).
“The great findings from the USP study helps us to better understand in the field of muscle research. Until recently, whey protein was believed to be the optimal choice of protein. This new research from the university proves that soy protein supports the muscle just as well when supplemented with a plant-based diet. With a vegan group showing the same muscle gains as whey protein, it does give us a little different message about this specific population,” she said.
“With the promising results from this new study, it may encourage greater use in other categories such as dietary supplements and performance nutrition products with better-for-you options,” added Peters.
Dr Roschel and his co-workers recruited 38 young men (19 omnivores and 19 vegans, mean age = 25) and put them into a supervised weight training program comprised of two weekly training sessions for three months. All the men had their diets adjusted to include 1.6 grams of protein per kilogram of body weight, with the vegans receiving soy protein (SUPRO XT 221D IP, IFF) and the omnivores receiving whey protein (THERMAX 690, Glanbia Nutritionals).
“Previous studies have compared the effects of supplemental protein of different sources (plant vs. animal) on muscle mass with contrasting results,” explained the researchers. “However, these studies investigated the addition of either a whey or soy protein supplement to an omnivorous diet, which does not provide an answer to the question of how exclusively plant vs. omnivorous diets impact muscle adaptations with [resistance training].”
The results of the new study showed that leg lean mass, whole muscle, and muscle fiber cross-sectional areas, as well as leg-press 1RM all significantly increased in both groups, with no differences between the groups.
The new data “challenge the notion that an exclusive plant-based diet is less efficient than an omnivorous diet to support muscle anabolic adaptations to chronic [resistance training],” wrote the researchers.
Potential differences in the availability of essential amino acids between the groups have been mitigated by the inclusion of whole foods such as grains and beans may have provided a more “complete protein” for the plant-based participants.
Dr Roschel and his co-workers added a note of caution in their paper, stating that the vegan group required approximately 58 grams per day of supplementary soy protein to meet the targeted protein intake, compared to about 41 grams per day of whey protein in the omnivore group.
“Therefore, our results are confined to a vegan diet with a relatively large supplemental plant protein isolate intake as a practical way to achieve adequate total intake (1.6 g kg−1 day−1) when dietary protein is obtained exclusively from plant sources,” they stated.
Sports & Active Nutrition Summit - USA 2022
Protein is just one of the many topics lined up for the upcoming Sports & Active Nutrition Summit, hosted by NutraIngredients-USA in association with the American Herbal Products Association's Sports Nutrition Committee. The event will take place in sunny San Diego Feb 14-16, 2022. For more information and to register, please click HERE.
Source: Sports Medicine
2021, Volume 51, Pages 1317–1330. Doi: 10.1007/s40279-021-01434-9
“High‑Protein Plant‑Based Diet Versus a Protein‑Matched Omnivorous Diet to Support Resistance Training Adaptations: A Comparison Between Habitual Vegans and Omnivores”
Authors: V. Hevia‑Larraín et al.