One of the first things that people ask about if they're seriously asking me about vegetarianism and aren't hung up on the animal rights thing is, But how do you get enough protein? You have to be SO careful about what you eat!

To them i usually respond, i eat a variety of things. That is usually enough. Having read (and been heavily influenced by) Diet For a Small Planet when quite young, i was interested to see this revision from Frances Moore Lappé on the subject of protein complementarity, a concept that she popularized in that book.

From Diet for a Small Planet, Tenth Anniversary Edition, Frances Moore Lappé:

When I first wrote Diet for a Small Planet in 1971, the idea that people could live well without meat seemed much more controversial than it does today. I felt I had to prove to nutritionists and doctors that because we could combine proteins to create foods equal in protein usability to meat, people could thrive on a nonmeat or low-meat diet. Today, few dispute that people can thrive on this kind of diet. In fact, more and more health professionals are actually advocating less meat precisely for health reasons. ...

In 1971 I stressed protein complementarity because I assumed that the only way to get enough protein (without consuming too many calories) was to create a protein as usable by the body as animal protein. In combatting the myth that meat is the only way to get high-quality protein, I reinforced another myth. I gave the impression that in order to get enough protein without meat, considerable care was needed in choosing foods. Actually, it is much easier than I thought.

With three important exceptions, there is little danger of protein deficiency in a plant food diet. The exceptions are diet very heavily dependent on fruit or on some tubers, such as sweet potatoes or cassava, or on junk food (refined flours, sugars, and fat). Fortunately, relatively few people in the world try to survive on diets in which these foods are virtually the sole source of calories. In all other diets, if people are getting enough calories, they are virtually certain of getting enough protein.

Please pay close attention to the last paragraph. This means that those who eat junky (refined, how's that for irony) foods are more likely to be protein deficient than a vegetarian who eats eclectically (dangu! is that a word?). Of course, it's also a warning to certain fruititarians, i suppose.

This doesn't mean that some people won't have problems getting the protein they need: their lifestyle may require that they get more (weightlifters, etc., for example), or they may have other health considerations. But there are more important nutrients that you need to be sure to get, like B vitamins, which are relatively uncommon from vegetable sources (hint: brewer's or nutritional yeast - yummy).

Our friend Protector of Mankind rebuts,

Maybe vegetarians who love cooking and have been at it for a while will have no problem because they will do it naturally because of their love of all things whole and good but I think if you're just starting out you should not depend on protein taking care of itself and you should try and balance meals properly with protein in mind (also taking vegetarianism, vitamins and minerals into consideration).
It's true, protein is not a non-issue, especially for new vegetarians, especially for those who were not raised, as i was, in a household where a variety of food was made at home from whole and fresh ingredients (and provided a focus of the day: food is not just about nutrition!). I suppose i haven an unfair advantage. However, sources that i have read say that Americans on average consume 2 - 5 times more protein than they need (probably because of their overconsumption of meat, and of food in general). The Vegetarian Society of the UK (www.vegsoc.org) says "it would be very difficult to design a vegetarian diet that is short on protein".

The issue of complete proteins comes up because proteins that our bodies use to build and regenerate themselves are themselves made up of amino acids; and while most food substances contain amino acids, not all of them contain a full set of the 8 considered essential to humans, or a complete protein. Animal protein, being made up basically of the same thing as us, will provide us with our essential amino acids, guaranteed. However, if that is out, there are plenty of plant sources that will provide all 8. Grains (such as rice) and legumes (you know, beans) are excellent sources, and balance each other out: the grains tend to lack the amino acid lysine, while the legumes tend to be short on methionine. Combining them is a good idea, however, they don't necessarily have to be combined in one meal. A good plan would be to include one such good protein source in each meal throughout the day (and be sure to eat several meals!) If you eat dairy and eggs, your task is further simplified with respect to proteins.

Too much protein is also not without its risks. It is not only wasteful (unused protein is not stored in the body), but it has been linked to cancer and osteoporosis due to inhibited calcium uptake. Because excess protein in the bloodstream is processed through the kidneys, it may also cause damage to your kidneys. Of course, these studies are always fallible, but i'll take my warning.

Oh, and: food can be a great source of satisfaction, creative and aesthetic as well as physical, in your life. So if you don't love to cook now, don't just make do with whatever's around that doesn't have meat in it.