A new study from the University of Illinois suggests that muscle building can be effectively supported by either a vegan or omnivorous diet, debunking the myth that animal-based proteins are superior.
Exciting new research from the University of Illinois challenges the conventional wisdom that animal-based proteins are superior for muscle building. The study, published in the journal Medicine & Science in Sports & Exercise, reveals that both vegan and omnivorous diets are equally effective in supporting muscle protein synthesis during a weight-training regimen.
“The longstanding belief or the current dogma was that animal-based protein sources were better, particularly for the muscle-building response,” Nicholas Burd, a professor of health and kinesiology at the University of Illinois Urbana-Champaign, who led the study with former graduate student Andrew Askow, said in a news release.
This belief has been rooted in the results of previous studies that showed a greater muscle protein synthesis response following animal-based meals compared to vegan ones. However, those studies only looked at the immediate effects after a single meal, which might not paint the full picture.
Leading up to their trial, Burd and his colleagues hypothesized that the habitual consumption of a balanced vegan diet over a more extended period might yield different results compared to those earlier, short-term studies.
They also wanted to explore whether a moderate protein intake distributed evenly throughout the day would affect muscle growth.
The study recruited 40 healthy, physically active adults, ages 20 to 40, who were subjected to a nine-day diet and weight training regimen.
They consumed either a vegan or omnivorous diet, and their protein intake levels were set to a moderate range of 1.1-1.2 grams of protein per kilogram of body weight per day. This protein intake is closer to what individuals typically consume in a standard diet, making the findings more applicable to real-world scenarios.
The participants underwent a seven-day “habituation diet” to standardize their nutritional status before the trial, and were then randomly assigned to either the vegan or omnivorous diet.
The omnivorous meals included a variety of animal proteins, while the vegan diet ensured a balanced amino acid content using whole foods.
Regardless of whether the protein consumed was of plant or animal origin, and whether it was distributed evenly throughout the day or varied across meals, the study found no significant differences in the rates of muscle protein synthesis.
“It was thought that it was better to get a steady-state delivery of nutrients throughout the day,” Burd added. “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.”
The participants engaged in muscle-strengthening activities every three days and were monitored using accelerometers.
Additionally, they drank “heavy” water labeled with deuterium to trace the incorporation of amino acids into muscle tissue, allowing for precise measurements of muscle protein synthesis through tissue biopsies.
Burd hopes that these findings will help dispel misconceptions about the necessity of animal-based proteins for effective muscle building.
“Now, if anyone asks me what’s the best type of food they should eat for muscle building, I’ll tell them: ‘It’s the kind you put in your mouth after exercise. As long as you’re getting sufficient high-quality protein from your food, then it really doesn’t make a difference’,” Burd added.
The research was financially supported by the Beef Checkoff program, overseen by the National Cattlemen’s Beef Board, though the sponsor played no role in the study’s design, data collection, analysis, interpretation or reporting, according to the researchers’ conflict of interest statement.