Protein, which is essential for life, is responsible for building and maintaining body tissue. Protein also plays a role in the formation of enzymes, hormones and body fluids. Healthy adults following a 2000 calorie diet need about 75 grams of protein per day, explains the Harvard School of Public Health. Higher protein intakes may aid in weight loss but further research is needed before concrete recommendations can be made.
Animal proteins are complete proteins. Complete proteins provide all essential amino acids, according to the Harvard School of Public Health. The protein content in 3 ounces of meat varies: cooked boneless chicken, 27 grams; roasted turkey, 25 grams; lean roast beef, 23 grams; ground beef, 24 grams; roasted pork trimmed of fat, 25 grams; ham, 21 grams; canned tuna, 23 grams; fresh tuna, 26 grams; salmon, 22 grams; shrimp, 21 grams; lobster, 17 grams.
Dairy foods, because they are animal products, also provide complete proteins, according to the Harvard School of Public Health. The protein content of commonly consumed dairy foods include 1/2 cup frozen yogurt, 2.5 grams; 8 oz. plain yogurt, 12 grams; 8 oz. of milk, 8 grams; 1 oz. of cheese, 7 grams; and 2 tbsp. of cream cheese, 4 grams.
Eggs are excellent sources of protein, reports the American Egg Board. One medium egg has 6 grams of protein; one egg white has 3.5 grams of protein.
Legumes, Nuts and Seeds
Legumes, nuts and seeds are good sources of protein as well as good sources of fiber, vitamins and minerals. Plant-based proteins are not complete, and the Harvard School of Public Health recommends eating a variety of plant proteins to meet essential amino acid needs. The protein content of legumes, nuts and seeds includes 1/2 cup cooked green soybeans, 11 grams; 1/2 cup cooked kidney beans, 8 grams; 1/2 cup chickpeas, 8 grams; 2 tbsp. chunky peanut butter, 8 grams; 1/4 cup of hummus, 5 grams; 1/2 cup peanuts, 19 grams; 1/2 cup almonds, 15 grams; 1/2 cup cashews, 10 grams; 1/2 cup walnuts, 10 grams; 1/2 cup sunflower seeds, 13 grams; 1/2 cup firm tofu, 10 grams; 1 cup plain soymilk, 10 grams.
Vegetables are another source of protein. The Northwestern Health Sciences University lists the protein in 1 cup of corn and broccoli as 5 grams. The protein content in other vegetables include 1 cup cooked spinach, 8 grams; 1 cup cooked artichokes, 6 grams; 1 cup cooked Brussel spouts, 6 grams; 1 cup cooked asparagus, 5 grams; 1 cup cooked okra, 4 grams.
The proteins in starch foods are incomplete, according to the Harvard School of Public Health. The protein content of common starches include 1 slice of whole wheat bread, 3 grams; 1 cup brown rice, 4.5 grams; 1 cup cooked pasta, 6.5 grams; 1 cup cooked oatmeal, 6 grams.