Should you use dairy or vegan protein to build stronger muscles?

Plant-based protein has been considered the lower quality option, but new research suggests otherwise

Woman drinking a protein shake
(Image credit: Getty Images)

If you're looking to build muscle, you'll want to add extra protein to your diet. Most people do this through protein powders, with dairy-based options like Whey and Whey Isolate among the most popular. 

But suppose you've been gradually moving towards a plant-based diet after picking up one of the best vegan cookbooks. In that case, you might be wondering which muscle-building protein supplements are available for you. 

For years though, a debate has raged about whether you can get enough protein from a plant-based or vegan diet. Likewise, the common perception is that non-animal protein powders are ineffective for developing muscle. 

However, a meta-analysis, a review of published research, found that "both animal protein and plant protein [support] an increase in absolute and percent lean mass." Notably, "there is no difference in effect between animal protein and plant protein on strength outcomes."

This confirms the results of a previous study, which observed no difference between soy and whey protein. But, as the latest review notes, this particular study only looked at soy, not all plant-based proteins. 

Similarly, all participants were involved in regular resistance training, so they worked to build muscle through exercise. The meta-analysis took a more comprehensive overview, including studies with a range of ages and fitness levels, with some exercising and others not. 

Despite this plant-powered positivity, the team did find that dairy-based protein led to an average 0.50% increase in lean mass compared to plant-based options. The effect was most noticeable in those under 50 as well. 

Man scoopoing protein powder

(Image credit: Getty Images)

Although the researchers weren't actively involved in these studies, they suggest that the differing performance may be down to the amount of amino acid in each type of protein. 

Animal protein, which also includes nutrients from meat and other dairy products, typically contains all the essential amino acids our bodies can't naturally produce.

Many single-source vegan protein powders, like pea, soy, or hemp, have these essential amino acids but in lower quantities. To compensate, you'd need to have additional servings or use a combination of supplements.

When discussing these findings, the authors note that "since percent lean mass takes into account body weight, it is [possible those] who consumed... animal protein experienced a greater loss or lesser gain in body weight (fat) over time."

They suggest that this "is because the ingestion of animal protein may induce higher energy expenditure than plant protein, possibly due to its greater anabolic effect." 

While this analysis shows some differences between the two protein sources, they are much more similar and effective than previously thought, especially when it comes to developing muscular strength. 

As the differences were only found in the under-50s, it may make sense for older adults to switch to plant-based options. We've known for a while that in our senior years, cholesterol becomes more of a concern. 

Previous research discovered that going vegan can cut your risk of heart attack and stroke, as it promotes protective HDL cholesterol while lowering harmful CDL levels. 

This recent meta-analysis focused on the muscle-building effects of protein, but there's another critical reason to consider adding supplements to your diet; weight loss. 

The best protein powders for weight loss include a mix of dairy and plant-based options and are designed to promote muscle growth without adding lots of calories to your diet. 

James Frew
Fitness Editor

James is a London-based journalist and Fitness Editor at Fit&Well. He has over five years experience in fitness tech, including time spent as the Buyer’s Guide Editor and Staff Writer at technology publication MakeUseOf. In 2014 he was diagnosed with a chronic health condition, which spurred his interest in health, fitness, and lifestyle management.

In the years since, he has become a devoted meditator, experimented with workout styles and exercises, and used various gadgets to monitor his health. In recent times, James has been absorbed by the intersection between mental health, fitness, sustainability, and environmentalism. When not concerning himself with health and technology, James can be found excitedly checking out each week’s New Music Friday releases.