New Study Finds Vegan Protein Helps Build Muscle

WASHINGTON — Protein is a key macronutrient that goes beyond muscle-building; you need it for your bones, heart, cognition and immune system. However, as anyone trying to gain or retain muscle knows, you need a certain amount of protein in combination with resistance training.

If you’re tuned into the muscle-building niche of the fitness world, you know there are more debates on the topic: which type of protein works best, how much do you need per day, and does it matter when you consume it? A new study provides some answers. Here’s what to know.

Protein and Muscle-Building: How it Works

When you do resistance training — whether it’s weightlifting or bodyweight exercises — you are breaking down your muscle fibers. After this type of exercise, consuming food rich in protein helps repair and regenerate your muscles, stimulates muscle protein synthesis, and initiates the process of muscle growth.

Animal vs. Plants

Protein consists of 20 amino acids: 11 are non-essential, and nine of them are essential, meaning that your body cannot make them on its own; you need to get them from food. For muscle growth to occur, your body needs “complete” protein sources — foods or supplements that contain all 20 amino acids.

Most animal-based protein sources, such as poultry, beef, fish and eggs, are complete proteins. Not all types of plant-based protein are. Previous research has suggested that animal-based protein stimulates muscle growth more than vegan protein, with the lack of complete proteins being one potential reason.

How Much Protein Per Day?

According to the American College of Sports Medicine, active people need 1.2 to 1.7 grams of protein per kilogram of body weight to gain muscle. 

Other guidelines, based on research by the International Society of Sports Nutrition, suggest that to reach your protein intake goal, aim for 30 to 40 grams of protein per meal, evenly distributed and spaced every three to four hours.

Impact of Vegan Diets on Muscle Protein Synthesis: A Randomized Controlled Trial

The previous research and guidelines seem strict and may work best for people dedicated to training hard and consuming a lot of protein, including supplements. Researchers at the University of Illinois challenged these ideas in a new clinical trial, published in the Journal of Medicine & Science in Sports & Exercise in April 2025. They investigated:

• Does animal protein work better than vegan protein?
• Can you build muscle with a diet of whole foods, aiming for a more moderate intake of 1.1 to 1.2 grams of protein per kilogram of body weight?
• Does it matter if you evenly space and balance your protein intake?

Participants

There were 40 participants, 28 men and 12 women, who were healthy and physically active. They were 21 to 29 years old.

Trial Design

All participants followed a seven-day standardized diet before the trial began. 

During the trial, they followed a weight-maintenance diet with 1.1 to 1.2 grams of protein, from either omnivore or vegan sources, per kilogram of body weight. 

They performed full-body resistance training workouts three times.

Groups

Participants were split into two initial groups:

• The omnivore group obtained 70% of their protein from animal sources.
• The vegan group consumed complete protein from plant-based sources.

Next, researchers divided the vegan and omnivore groups further to examine how the amount of protein per meal would affect muscle growth. Each was split into two groups, making a total of four.

• The balanced groups ate the same amount of protein (20% of their daily intake) between five meals or snacks.
• The unbalanced groups varied their protein content across three meals, consuming more protein at the end of the day. They consumed 10% of their protein at the first meal, 30% at the second, and 60% at the third.

Muscle Growth Measuring

Participants consumed heavy water each day, which helped researchers trace and measure daily rates of muscle protein synthesis. 

Results

Here is what they found.

• The omnivore groups consumed more carbohydrates in their daily calories than the vegan groups. There were no other differences in nutrient intake.
• There were no differences in muscle protein synthesis between the omnivore and vegan groups.
• There were no differences in muscle protein synthesis between the balanced and unbalanced groups; evenly distributing protein or eating more at one meal did not make a difference.

Future Implications

When it comes to protein, a new clinical trial states you may not have to overthink it. Animal or plant sources can both help you build muscle when you are following a resistance training program — just make sure you get complete protein from your vegan sources. It also highlights that you don’t need to perfectly space and time your protein intake throughout the day — the overall amount matters most.

Our website content, services and products are for informational purposes only. The Well News does not provide medical advice, diagnosis or treatment. If you have medical concerns or questions, discuss with your health care professional.

You can reach us at [email protected] and follow us on Facebook and X