Protein is a macronutrient commonly known as the "building block" of muscle. There are plenty of foods not only high in protein but also high in fat and carbohydrates, so it's important to choose the right sources. High-protein diets are commonly used by athletes seeking to build or maintain muscle mass. The American Heart Association does not recommend high-protein diets for weight loss.
Meats top the list of the foods with the highest amount of protein. According to the Harvard School of Public Health, a 6-ounce broiled porterhouse steak is a great source of protein, with 38 grams total. It also delivers 44 grams of fat, however, 16 of which are saturated. A healthier choice would be salmon, with 34 grams of protein and only 4 grams of saturated fat per 6-ounce serving. Other meats that are good sources of protein are chicken breast, with 29 grams per 4-ounce serving; turkey breast, with 34 grams per 4-ounce serving; sardines, with 22 grams per can; and tuna, with 32 grams per 1/2 cup serving.
Dairy products are also high on the list of the best sources of protein. Greek yogurt tops the list with 20 grams of protein per 1 cup serving. Regular yogurt contains 10 to 12 grams per cup, while cottage cheese contains 15 grams per 1/2 cup serving. One egg contains 6 grams of protein and one egg white has 3.5 grams. Swiss cheese has the most protein of all cheeses, with 8 grams per 1 ounce serving. Milk has 8 grams of protein per cup.
Grains are another good source of protein. Whole grains have more protein than refined or "white" grains. Oatmeal contains 6 grams of protein per cup, while quinoa has 9 grams per cup and bulgar wheat contains 8 grams. One slice of whole wheat bread has 3 grams of protein and 1 cup of whole wheat spaghetti has 8 grams.
Nuts and Seeds
If you happen to be vegetarian, nuts are an excellent source of non-meat protein. Pumpkin seeds have 19 grams of protein per 1/4 cup serving. Peanuts have 9 grams of protein per 1/4 cup serving and 1/4 cup of almonds or flax seeds has 8 grams. Two tbsp. of peanut butter have 8 grams and 1/4 cup of sunflower seeds has 6 grams.
Vegetables and Legumes
Beans and legumes are among the best sources of protein. One cup of soy beans has 28 grams of protein, while tofu has 20 grams of protein per cup, followed by lentils with 18 grams per cup, black beans with 15 grams and kidney beans with 13 grams. One cob of sweet corn contains 5 grams of protein and a medium-size baked potato with the skin contains 5 grams as well. One cup of spinach has 5 grams of protein and avocados and artichokes contain 4 grams each.