Can you build muscle on a plant-based diet?

For adults over 55, both vegetarian and omnivorous diets combined with resistance training increased muscle mass and strength. However, the vegetarian group actually hit lower protein targets and saw slightly less muscle gain than the meat-eating group.

Test your knowledge

If a person over the age of 55 wants to maintain muscle mass while switching to a plant-heavy diet, which of the following best describes the primary challenge they face based on this study's findings?

A) A plant-based diet is inherently incapable of building muscle, regardless of how much protein is consumed.
B) It is significantly harder to reach the same muscle mass gains on a plant-based diet compared to an animal-based diet, even when protein targets are met.
C) Both diets can successfully build muscle and strength, but the plant-based group actually consumed more total protein to do so.
D) The type of protein (plant vs. animal) is the only factor that determines whether an older adult can improve their physical strength.

🔬 The Breakdown

Context: This confirms that while plant-based proteins are viable for health, meeting specific protein targets is a logistical hurdle that often requires more intentional planning than simply eating animal products.

Reality Check: Hitting 1.2g of protein per kilogram of body weight can be difficult when relying on cheaper, high-volume plant foods that aren't as protein-dense as meat.

Takeaway: Prioritize high-protein plant staples like lentils, chickpeas, and soy to hit your daily protein goals without increasing your grocery bill.

Published September 23, 2026

The science, explained

Evidence Check: This was a randomized controlled trial of 108 adults aged 55 and older.

Conventional Wisdom Check: This refines the common belief that any high-protein diet is equal by showing that a plant-heavy diet may fall slightly short of the results seen with animal proteins.

Everyday Translation: While both groups got stronger, the group eating more animal protein saw a larger increase in actual muscle mass than the vegetarian group.

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