Vegan vs Omnivore Diet for Muscle Growth and Strength

Gaining strength and muscle: What science says about vegan vs omnivore diets

We know that muscle growth comes down to getting enough protein, which can be difficult for vegans given plant-based sources don't contain as much. And it's no small number: current protein recommendations for muscle growth is 1.7 grams - 2.6 grams of protein per kilogram of body weight per day.

The other hindrance for vegans is the amino acid leucine; one of three BCAAs and key regulators behind muscle growth. The simple fact is that plant proteins are lower in leucine. Moreover, we need about 40-45 mg of leucine per kilogram of body weight per day. So, somebody who is 80 kilograms will require 3.6 grams of leucine per day. 

So, when we talk about their being "truth" to vegans having a hard time growing muscle, this is what we're referring to. But how much of an issue is this really for vegans? 

Well, research conducted in 2021 more or less asked this question, endeavouring to find what happens when you match the protein in the diet of a vegan and omnivore, have them perform weight training, give them protein powder supplements, and see who gains more muscle and strength.

Specifically, the untrained young men supplemented with either whey protein powder (the omnivores) whilst the vegans were given soy protein powder. They also consumed diets in whole foods.

The study consisted of 19 habitual vegans and 19 omnivores aged in their 20s. They did a 12 week, twice weekly, resistance training program under supervision from researchers, and consumed ~1.6 grams of protein per kilogram of body weight, per day. The lean mass of their leg, whole muscle, and muscle fibre cross-sectional area was assessed, along with leg press 1RM, both before and after the study.

So, what did they find?

Both the omnivores and vegan groups showed significant increases in their leg mass; all three major parts of the quadriceps! But which group gained more muscle?

They both gained the same!

This led the researchers to conclude that 1.6 grams of protein per kilogram of body weight per day, from either mixed whole foods and whey protein supplementation, or plant-based whole foods and soy protein isolate supplementation, is the same for muscle growth and strength. The researchers add:

"...protein source does not affect resistance training-induced adaptations in untrained young men consuming adequate amounts of protein."

Now it's important to point out that these subjects were untrained, and that doesn't necessarily translate into all populations. One of the study's authors, Hamilton Roschel, added this commentary:

“Aging entails a phenomenon known as anabolic resistance, meaning a suboptimal anabolic response to the stimuli provided by diet and exercise compared with young people. Optimal response is possible in older people only if their protein intake is higher than that of the average healthy youngster. So, we should be cautious about generalising our findings for the entire population.”

In other words, if you're an older vegan, eat EXTRA protein and consume more leucine! And such comments are in line with previous research we've told you about here before; vegans may need to eat more protein than is recommended just in case. And this is particularly relevant to older vegan gym-goers.

But the bottom line is that by getting adequate protein and specifically, leucine, muscle growth shouldn't be different for vegans and omnivores. And we've catered for vegans here at Bulk Nutrients, with at least three products that aim to boost your protein and leucine requirements:

Honourable mentions are our Pea Protein or Rice Protein variety!

But it boils down to this: if you're a vegan, make sure you eat enough protein, consume enough leucine via your vegan protein supplements -- and rub this article in the face of your omnivore friends!