Non-meat sources of vegetarian protein are really quite simple to find. One of the key things to learn is how to eat to get all the amino acids – sometimes called a ‘complete protein’.
In order for vegetarian diets to contain a healthy amount of protein, they must contain a variety of plant proteins to form complete amino chains. There is no one plant that has a complete protein. Complete proteins are important because your body needs them to create muscle tissue.
Combining grains like rice with legumes like dried beans will give you that complete mix of amino acids. A classic example is a peanut butter sandwich (on whole wheat bread!). It’s a great combination. Black beans and rice is a favorite Hispanic dish.
By eating vegetables, legumes, seeds, nuts, fruits, and whole grains, vegetarians can increase the amount of complete proteins they create by combining a number of varieties of amino acid chains.
Although most vegetarians consume a considerable amount of protein, they often do not absorb as much as they would on a non-vegetarian diet. This is because plant proteins are considerably less digestible than animal proteins, which contain amino acid chains that are closer or identical to human amino acid chains.
Consuming animal proteins might yield close to a 1:1 absorption ratio, while consuming plant proteins, such as wheat, might only yield 50% of the amino acids needed to build a "complete protein" or a protein that can readily be assimilated into the human body.
For non-vegan vegetarians, yogurt, milk, and eggs (which contain complete proteins) are all excellent sources of protein.
Because plant proteins are generally harder to digest, vegetarian diets need to include more grams of protein than a meat eater. While a nutritional label may suggest that pasta has 5 grams of protein per serving; you may only be able to digest 2-3 grams of that protein, which means you must complement the pasta with other sources of protein. A bit of cheese would do the trick.
In addition to natural sources of protein, vegetarians should also seek foods that are "protein-fortified"–
or artificially-infused with protein. For example, many supermarkets offer a variety "protein-fortified" pasta and bread. I have seen pasta that contains as much as 12 grams of protein per serving.
Soy milk is also a good source of protein for vegetarians. Studies on isolated soy protein show that it can be absorbed nearly as well as animal proteins, yielding close to a 1:1 protein absorption ratio. Be careful not to rely to heavily on soy as a protein source. Isolated soy protein is a manufactured food that’s made from the residue left over from pressing soybean oil. There’s nothing ‘natural’ about it.
Vegetarian foods can give you the complete proteins you’re looking for. Learn to mix and match them correctly and you’ll have no problems getting enough protein into your diet.