The Vegetarian Protein Supply and How to Complete Your Beans

Legumes are deficient in an essential amino acid called methionine. If soybean (used to make tofu) is a major source of protein for non-meat eaters, how can total vegetarians avoid being protein deficient?

One of the first questions many people ask when they learn of my vegetarian diet is: Where do you get your protein? My answer is, from a source very similar to where a horse gets his.

Well, no. You don't actually expect me to say that. That would not be so nice, but it's true. My protein comes from plant sources. Realizing that most non-vegetarians are sincerely ignorant about the meatless diet, I usually give examples of the types of foods they would find in my meal.

I usually get a complimentary, "that's healthy!" comment.

Here is the answer to a deeper form of the original question. As noted earlier, a major source of protein for total vegetarians and vegans is bean curds or tofu. Now, the legume family is deficient in one of the essential amino acids - methionine - how do total vegetarians and vegans get their protein?

Before answering this question, it is interesting to note that a comparison of the major amino acids in beans, eggs, and beef is surprising. The only difference is the methionine content. So here is how vegetarians complete their beans ...

Although beans are deficient in methionine, the grains such as wheat, rice, corn, and oats are great sources of methionine; also sunflower seeds. So getting all the building materials to make complete protein is not a problem. A serving of rice and beans provides all the essential amino acids needed to complete your protein intake. But that's not all.

You don't get all that fiber and foliate from meat that you get from beans. A 100 gram serving of beans provides more than 50% of your RDA of fiber and more than your RDA of iron for a man.

For those who wonder if plant sources of protein are adequate, next time you see a horse, just take a look at how plants can build muscles.