Plant proteins might not help older people build or keep muscle as well as animal proteins because they're harder to digest and don't have as much of the important building blocks muscles need.

Some plant proteins don't help build muscle as well as animal proteins because they often don't have enough of certain important building-block nutrients, especially lysine and methionine, which are low in foods like wheat, corn, and oats.

Plant proteins like soy and wheat don’t help build muscle as much right after eating compared to animal proteins like whey or milk, especially in older people when they're not exercising.

Eating more plant protein—like 60 grams of wheat protein in one meal—might help older adults build muscle just as well as smaller amounts of animal protein, like whey, even though plant proteins aren't as easily used by the body.

If you're a healthy young adult, eating 20 grams of plant protein from peas and canola will help your muscles grow a little after fasting, but not as much as drinking whey protein — so animal-based proteins are better at building muscle without added supplements.

Eating larger amounts of plant protein, like wheat, can build muscle just as effectively as eating animal proteins like whey.