‘Bro-Science’ Overturned: Plant-Based Diets Build Muscle Just as Well as Animal Proteins

Study Finds ^ | April 21, 2025 | Research led by Andrew Askow and Nicholas Burd, University of Illinois Urbana-Champaign

[Red Badger]

In a nutshell

Vegan diets support muscle protein synthesis at the same rate as omnivorous diets when protein intake is matched (1.1-1.2g per kg of body weight).

How you distribute protein throughout the day (evenly across meals vs. mostly at dinner) doesn’t significantly impact muscle growth.

Vegan dieters reported higher energy levels and less fatigue, while omnivorous dieters reported greater meal satisfaction.

*******************************************************************

CHAMPAIGN, Ill. — Forget what you’ve heard at the gym about needing chicken breasts and steaks to build muscle. Science just delivered a win for plant-based eaters everywhere. Researchers found that vegan diets support muscle growth just as effectively as those loaded with animal proteins, according to a new study.

“Bro-science” at fitness centers has long claimed animal proteins are essential for serious gains. This misconception has fueled a massive supplement industry pushing whey protein and other animal-derived products as muscle-building necessities. The new research published in Medicine & Science in Sports & Exercise says is great news for those interested in moving more towards plant-based diets.

The Science Behind the Study

The University of Illinois Urbana-Champaign team, led by Andrew Askow and Nicholas Burd, discovered that when protein intake is matched, there’s no difference in how quickly muscles create new proteins—regardless of whether that protein comes from plants or animals.

The researchers studied 40 healthy, active young adults who followed either vegan or omnivorous diets for nine days while completing resistance training. Both groups consumed the same amount of protein daily (about 1.1-1.2 grams per kilogram of body weight). Using techniques involving heavy water and muscle samples, the scientists directly measured muscle protein synthesis rates—the process responsible for muscle growth.

In the paper, the researchers state: “Our results demonstrated that the anabolic action of animal vs. vegan dietary patterns are similar.” This finding directly contradicts long-held beliefs about animal protein superiority.

Animal protein vs Plant protein for muscle-building

It’s been a heavyweight debate for years now, but the latest research shows animal protein is no better than plant-based protein when it comes to building muscle. (Graphic by Michael B. Vincent)

Protein Timing Myth Busted

The researchers also tested whether protein distribution evenly throughout the day matters. Half the participants in each diet group consumed their protein in three uneven meals (10%, 30%, and 60% of daily protein), while the other half spread their protein intake evenly across five meals (20% each).

Despite popular theories suggesting that even protein distribution is optimal, the study found no significant difference between these approaches.

“There was no effect of dietary pattern or protein distribution on the stimulation of myofibrillar protein synthesis rates,” the researchers reported. Simply put, whether participants ate animal or plant proteins, and regardless of how they timed their meals, their muscles synthesized new proteins at similar rates.

The data rebuts theories suggesting precise meal timing and protein distribution are critical for muscle development. Exercise appears to enhance the body’s ability to use both protein types effectively, minimizing differences between animal and plant sources.

Mental and Physical Benefits

Interestingly, the study uncovered psychological differences between the diet groups. Participants following omnivorous diets reported “greater feelings of pleasantness” compared to those on vegan diets. However, the vegan group reported “higher feelings of energy and lower feelings of tiredness.” This suggests that while vegan diets may support equal muscle growth, they might also offer some advantages for energy levels during training.

The findings come at a time when plant-based eating continues to gain popularity, with many people reducing animal product consumption for health, environmental, or ethical reasons. This research provides reassurance that those choosing plant-based diets can achieve their fitness goals without compromise.

For athletes, fitness enthusiasts, and anyone concerned about maintaining muscle mass while reducing animal product consumption, the implications are straightforward: protein quality matters less than overall diet quality and consistent resistance training. You can build muscle effectively without animal products if you consume sufficient total protein from varied plant sources.

Paper Summary

Methodology

The researchers conducted a randomized controlled trial with 40 healthy, physically-active young adults (28 males, 12 females, average age 25 years). Participants were randomly assigned to one of four groups: omnivorous diet with balanced protein distribution (OMN-B), omnivorous diet with unbalanced protein distribution (OMN-UB), vegan diet with balanced protein distribution (VGN-B), or vegan diet with unbalanced distribution (VGN-UB). All participants consumed 1.1-1.2 g/kg/day of protein. The balanced distribution consisted of five meals with 20% of daily protein at each meal, while the unbalanced distribution had three meals with 10%, 30%, and 60% of daily protein. Participants completed a 9-day resistance training intervention with three supervised whole-body resistance exercise sessions. Researchers measured myofibrillar protein synthesis using deuterated water (D2O) consumption and muscle biopsies from the vastus lateralis (thigh muscle).

Results The study found no significant differences in myofibrillar protein synthesis rates between any of the groups. The rates were 3.04±1.85%/day for OMN-UB, 2.43±1.21%/day for OMN-B, 2.52±1.77%/day for VGN-UB, and 2.49±1.56%/day for VGN-B. This indicates that both vegan and omnivorous diets supported similar muscle protein synthesis when protein intake was matched. The protein distribution pattern (balanced vs. unbalanced) did not affect muscle protein synthesis rates either. The study also assessed psychological well-being and found that participants on omnivorous diets reported greater feelings of pleasantness, while those on vegan diets reported higher energy and lower tiredness.

Limitations

The study was conducted over a relatively short period (9 days), so long-term effects remain unknown. The sample size (10-11 participants per group) was relatively small. All participants were young (20-40 years) and healthy, so results may not apply to older adults or those with health conditions. The researchers note that resistance exercise may have enhanced the anabolic response to both dietary patterns, potentially eliminating subtle differences between animal and plant proteins that might exist in less active individuals.

Funding and Disclosures

The study was funded by The Beef Checkoff, which could potentially introduce bias since the organization represents beef producers. However, the researchers stated that “Beef Checkoff sponsor was only involved in financial support of the project, without involvement in design, data collection, and analysis, nor interpretation and dissemination of the report.”

Publication Information

The study “Impact of Vegan Diets on Resistance Exercise-Mediated Myofibrillar Protein Synthesis in Healthy Young Males and Females: A Randomized Controlled Trial”

was published in Medicine & Science in Sports & Exercise in March 2025 (accepted March 29, 2025).

The research was conducted by Andrew T. Askow, Takeshi M. Barnes, and colleagues from the Department of Health and Kinesiology and Division of Nutritional Sciences at the University of Illinois Urbana-Champaign. The study was registered with ClinicalTrials.gov (NCT04232254).

[Red Badger]

Well, the Beef Council paid for it..............

[Tailback]

Thank you for that response. I thought that was your aim, but, on the internet you never can tell.

[Songcraft]

Check out the teeth on this herbivore!   Some gorillas can lift over 1763 pounds of dead weight.   That's roughly twice as much as a well trained weightlifter.   (This guy could pick you up, and throw you across the room!)      🙂





Here is a chart showing a diagram of, among other things, gorilla teeth:





(By the way, I'm not a vegan, just the opposite.   For health reasons, I'm currently following a temporary carnivore diet (beef, eggs, fish --- except for holidays), as described on youtube by Dr. Shawn Baker, Dr. Anthony Chaffee, and Dr. Ken Berry.   I try to keep an open mind though about some of these other dietary alternatives (especially those of people doing special diets for religious motivations), and who knows what diet I may be following in the future.)

My personal goal in all these things is to seek the truth, the whole truth, and nothing but the truth, so help me Hannah!

[nopardons]

Go to were you have a mirror, look into it, open your mouth wide and LOOK AT TEETH! Do they look like what you posted to me?

Are YOU a gorilla or a human?

Though we and gorillas are both PRIMATES, not ALL primates have the same looking nor even amount of teeth.

Case closed.

[nopardons]

were = WHERE. Sorry about that!

[Songcraft]

You are totally missing the point.   Gorillas have very similar, but less teeth than we do, and they have much longer canine teeth than we do, more like carnivore animals.   They are herbivores, and, like I said, they could pick you up, and throw your ass across the room.   Meat-eating you could not even pick up a full-grown gorilla, let alone throw them anywhere.

Having more teeth does not indicate that they were meant for meat-eating.   In fact, in an emergency (very rarely), Gorillas can and do eat meat too, where sufficient plant foods are not available for some reason, and they do not need any extra teeth to do that.   They can eat meat just fine, but they always prefer plant foods when they are available.

Giraffes have 32 teeth just like humans, and they are also herbivores.

[nopardons]

I guess that you didn't have a biology section in science class when YOU were in middle school; I DID!

Human beings are meant to be OMNIVORES; it's our BIOLOGY!

A gorilla is not the same as a mandrill, a mandrill is not the same as a baboon, and NONE of them are exactly like HUMAN BEINGS, however, were are ALL primates.

Is a penguin, a cardinal, and a humming bird all alike, re their food intakes/DIETS? NO, of course they are NOT; but still and all....THEY ARE ALL BIRDS!

So WHY are you arguing with me, to what purpose? You aren't even a vegan!

[Sacajaweau]

The study was 9 days long. Groups of 10 people. All between 20-40.

What the hell kind of study is that??

[nopardons]

LOL...just another predetermined CRAP study.

[trebb]

I like beef....

[Red Badger]

Beef is food.

Vegetables is beef food..............

[Red Badger]

Beef is food.

Vegetables is beef food..............

[trebb]

I can go along with that - I like a lot of vegetables, but my favorite ones have been ingested/digested/turned to flesh.

[Harmless Teddy Bear]

No. They are not.

No more then Chimps are.

It's cute the way they deny the truth repeatedly because the idea of monkeys that eat meat just throws their entire "man was a plant eater" bull squeeze in the trash.

You would be on far firmer ground to bring in the panda. Who is a meat eater that went vegan. And has trouble staying alive even though it eats constantly and is legendary for it's inability to reproduce.

[Nifster]

But they don’t taste the same

[EasySt]

Perhaps not enough... ;-)

[Red Badger]

Yeah, and where are they now?

They’re both dead!.................🙄

[Songcraft]

"The study was 9 days long. Groups of 10 people. All between 20-40. What the hell kind of study is that??"

---

You should ask that question of the poster of that study and this thread.     🙂

Not sure if you're a Bible believer or not, but there is a dietary "study" very similar to this one, in the Bible.

Jesus studied and quoted from a prophet in the Old Testament named Daniel.   (See Matthew 24:15-16.)

In Daniel 1:3-21, there is a very similar small study between two different diets, and you might find that interesting.

[Songcraft]

Just a quick follow up, some time do a quick search on duckduckgo for --- famous vegan athletes --- and review some of the neutral (unbiased) results you get there.

[Songcraft]

"So WHY are you arguing with me, to what purpose? You aren't even a vegan!"

---

I told you in post 63, I like to learn the truth, and to be able to affirm that truth.   (Does a person have to be an Israeli, in order to support Israeli sovereignty?)

The fact of the matter is that all of these diets can be done in a healthy way, and all of them can also be done in an unhealthy way.

Meat eaters can have a healthy diet, and meat eaters can have an unhealthy diet.

Vegetarians can have a healthy diet, and vegetarians can have an unhealthy diet.

Vegans can have a healthy diet, and vegans can have an unhealthy diet.

For example, vegans could eat nothing but candy bars and still be following a vegan diet, and meat eaters could eat nothing but ribeyes and candy bars, and still be meat eaters.   Neither of those diets would be considered healthy by most people.

Here's Some More Famous Meat-Eaters

Jerrold Nadler
Very Strong (Strong Odor)

Chris Christie

Chuck Scummy Schumer

Nancy Polluted Pelosi

Admiral Rachel Levine

Sam Brinton

Adam Schiff

Abrego Garcia

Pete Buttigieg

Joe Biden