Quinoa, a plant-based protein source, contains all nine essential amino acids that are crucial for building muscle.
One cup of cooked lentils has about 18 grams of protein, which is more than the protein found in a three-ounce serving of chicken.
Peanuts are also high in protein, with eight grams of protein per one-quarter cup serving.
One cup of cooked broccoli contains about five grams of protein, making it a great vegetable protein source.
Soybeans are a complete protein source and contain up to 36 grams of protein per one-cup serving.
Oats are a good source of protein, containing about six grams of protein per one-cup serving.
Sunflower seeds are a great source of protein, containing about six grams of protein per one-quarter cup serving.