Vegetable proteins usually contain lower level of leucine10 compared to animal proteins. “For example,” Layman says, “grains like wheat and quinoa contain less than 7% leucine, while legumes like soybeans and peas contain about 8% leucine.” On the other hand, chicken breast contains about 12% leucine.

However, with careful diet planning, vegetarians and vegans can get enough leucine to support muscle growth and overall health.

Because plant proteins cannot provide optimal amounts of leucine on their own, people who eat plant-based foods can ensure adequate leucine intake by combination of different sources of vegetable protein11. For example, eating legumes, grains, nuts, and seeds can create a complete protein profile that contains all the essential amino acids, including leucine.

Additionally, prioritizing leucine-rich plant foods such as tofu, tempeh, edamame, pumpkin seeds, and some legumes can further increase your leucine intake.

“Vegetarians can easily get enough leucine from dairy and eggs,” says Church. “Vegans should consider additional protein sources such as corn, soy and rice. However, today’s commercially available protein isolates and essential amino acid supplements (usually from vegan sources) are high in leucine.”