Vegetarians are people who, for ethical or health reasons, do not eat meat--a source of protein in one's diet. Meat is responsible for giving you energy and building muscle, but you can also obtain protein from non-meat sources. The American Heart Association recommends choosing from a wide variety of protein sources to get enough nutrients in your diet.
One cup of cooked soybeans offers 29 grams of protein for your daily diet, according to The Vegetarian Resource Group. Soy products, such as tofu and tempeh, are derived from the soybean, and can replace meat in some recipes. An expanding market for soy products means you can find soy hot dogs, burgers, bacon and sausage in the freezer section of your local supermarket. Soy milk and other non-dairy products made with a soy base can be fortified with added nutrients to boost your energy.
Legumes are a low-cost food group that comes from edible seeds. They include commonly eaten beans, such as black, kidney, lima and baked beans--all of which have more than 10 grams of protein per cup, according to The Vegetarian Resource Group. Other examples include chickpeas, split peas, haricots and lentils. You can add these legumes to soups and casseroles for a main dish or serve them as a side dish.
Although some vegetarians may not consume eggs because they are an animal product, eggs are a complete protein source and a good source of energy. They contain the nutrient vitamin D, which may otherwise be missing from a vegetarian diet. You can also purchase egg substitutes and egg whites at most grocery stores.
If you eat enough protein, yet still feel devoid of energy, consider increasing your calorie intake. In addition to the energy your body derives from protein sources, your body also requires calories from foods that contain carbohydrates, particularly if you are an athlete or very active. Some foods offer both carbohydrates and protein; examples include whole-grain products, such as whole-wheat bread, bagels and cereals. Vegetables, nuts and seeds also offer complementary proteins.