Dear Alice, What are the best non-meat sources of protein? --Veggie
The best way to get ample protein with plant food is to eat a variety of fruits, vegetables, grains and beans. The protein in an individual plant food is almost always incomplete, meaning it is low in one or more essential amino acids. However, by eating a variety of plant foods such as whole grains (brown rice, whole wheat, barley, rye, buckwheat, millet etc.), legumes (dried beans and peas), nuts, seeds and vegetables, you will be combining foods with different amino acids and getting ample, complete protein. Tofu, texturized vegetable protein, and tempeh are soy bean products that contain a concentrated amount of protein. They provide a good complement to other plant-based food, but are not essential to a vegetarian diet.
Some sources say that exact amounts of specific foods need to be combined and consumed at the same meal in order to have a complete protein, such as 1/2 cup kidney beans with 1 cup rice (based on amino acid contents). This is not true, but it is important to have a variety of different plant foods each day in total. A diet of only brown rice, or only tofu would not provide a vegetarian with sufficient amounts of complete protein. In general, vegetarians who are on the "bagel and pasta diet" tend not to get enough protein, since both foods are wheat-based, and their protein would be incomplete.
Source: "Go Ask Alice" Columbia University's Health Question and Answer Internet Service