a protein is simply a long string of amino acids. most of them are flush along with other bodily waste, so you need to be sure that you are getting quite enough of them. happily, your body is good at synthesizing all but a few of them, which you must eat.
for simplicity, the best place to get them is from animal flesh, as it has the most "complete"(mix) proteins, being that animals are more similar to humans than, say, a pinto bean. that's one of the reasons vegetarians have to be so careful about what they eat. at any rate, you'll find that lot's of people have lots of ideas on what you need. some body builders might tell you you need 3 grams protein per kilogram of body weight, a marathoner might say you only need .5. there are a lot of studies on the cutting edge of science and right now is really exciting in everything dietary. the current recommendations for sub-olympic athletes is in the neighborhood of 2g per kg, or about .9 grams per pound of bodyweight. that's what i shoot for when i eat and i can say that lack of workout time hurts me WAY more than lack of protein. oh yeah, sorry but it doesn't work like a steroid. there are ways of manipulating your hormones (testosterone, growth hormone, cortisol, plus a few), but the effects will be minimal because the variance will be minimal. it's not like shooting the juice. anywho, good luck with the diet.