New Study Debunks Myths About Vegan Diets adn Muscle Growth

Updated June 4,2025
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A recent study challenges conventional wisdom regarding the impact of diet on muscle protein synthesis. researchers investigated whether the source of protein—plant-based or animal-based—affects⁤ muscle gain, if⁢ evenly distributing total daily protein intake⁣ matters, and if a moderate daily protein intake influences these variables. The surprising answer to all three questions ‍was “no.”

The findings appear⁤ in Medicine ⁣and Science in Sports and exercise.

Nicholas burd, a professor at ⁣the University of Illinois Urbana-Champaign, along with former graduate student Andrew Askow, spearheaded the research. Burd noted that the long-held belief⁤ that animal-based protein sources are superior for muscle building stems from earlier studies. These studies, involving muscle biopsies after single feedings, suggested animal-based meals stimulated muscle protein synthesis more effectively than vegan meals. Though, Burd argues that single-meal measurements may not accurately reflect the long-term effects of a balanced vegan diet.

The⁣ team⁣ aimed to determine if habitual consumption of diverse vegan or meat-based whole-food diets influences muscle protein synthesis ⁣over⁤ time. they also tested the hypothesis that a moderate protein⁣ intake—1.1-1.2 grams per kilogram of body weight daily—should be evenly distributed to maximize muscle growth.

The study involved 40 active ‍adults aged⁢ 20-40. Participants underwent a seven-day “habituation diet” to standardize their nutritional status before being randomly assigned to either a vegan⁢ or omnivorous diet. The research team⁤ provided all meals,‍ with‍ about 70% of the protein in the omnivorous diet coming from animal ⁣sources like beef, pork, chicken, dairy, and eggs. The vegan diet was carefully balanced to ensure participants ⁤consumed complete proteins.

Within ⁤both diet groups, participants were further divided into⁣ those who consumed roughly equal amounts of protein at each of three meals and those whose protein intake varied across five meals, with more protein consumed later in the day.

All participants engaged in muscle-strengthening activities⁢ every three days and wore accelerometers to track their activity levels. They also consumed “heavy” water, labeled with deuterium, to trace amino acid incorporation into muscle tissue. Muscle biopsies were taken at the beginning and end of the nine-day trial.

Burd⁤ expressed surprise that there were no significant differences in muscle protein synthesis between ‍the vegan and omnivorous groups.He was also surprised that protein distribution ⁢had no‍ effect, contradicting previous studies on acute responses to dietary interventions ⁤and weight training.

“It was thought‍ that it was better to get a ⁢steady-state delivery of ⁢nutrients throughout the day,” Burd ⁤said.”I also thought that if you’re getting a lower quality protein — in terms of its digestibility and ⁢amino acid⁤ content — that perhaps distribution would make a difference. ⁢And surprisingly, we showed it⁢ doesn’t matter.”

Now, Burd says, if anyone asks him what’s the best type of food they should eat for muscle building, he’ll tell‍ them: “It’s the kind you ⁢put⁤ in your mouth after exercise. Provided that you’re getting sufficient high-quality protein from‍ your food, then it really doesn’t make a difference.”

What’s next

Future research may explore the long-term ‍effects of different ⁤dietary⁢ patterns on muscle health and overall well-being, focusing on diverse populations and varying levels of physical activity.