Protein is made of building blocks called amino acids. Although the human body can make some of these amino acids, nine of them (the essential amino acids) must be obtained from food. Soy foods and animal sources of protein (milk, eggs, meat, poultry, fish, and seafood) contain all the essential amino acids in the amounts our bodies need.
Most plant foods contain some of the essential amino acids in varying amounts. Beans have some amino acids, and grains have other amino acids. Eating these different types of food throughout the day will provide your body with adequate protein.
Foods that contain protein
Most adults should eat 5 to 7 ounces of protein foods a day.
Lean meat, poultry, or fish. A cooked serving is 2 to 3 ounces. (3 oz is about the size and thickness of a deck of cards or the palm of your hand.) You can use your hand to judge other portion sizes.
Protein isn't just found in meat. If you are a vegetarian or just looking for alternatives to meat, the following are equal to approximately 1 oz of meat:
¼ cup cooked beans, peas, or lentils
¼ cup tofu (about 2 ounces)
2 Tbsp hummus
½ ounce nuts or seeds (for example, 12 almonds or 7 walnut halves)
1 Tbsp peanut butter or other nut or seed butter
Other sources of protein include cheese, milk, and other milk products.
You can also buy protein bars, drinks, and powders. Check the nutrition label for the amount of protein in each serving. Protein supplements can be helpful if you are trying to replace weight, heal, or recover from illness or surgery. It's important to choose real foods that are high in protein first, before trying a protein supplement.
Medical Review:Kathleen Romito MD - Family Medicine & Rhonda O'Brien MS, RD, CDE - Certified Diabetes Educator