Subscribe to fitness and nutrition email updates.
Proteins are an important part of your bones, muscles, and skin. In fact, proteins are in every living cell in your body. Inside cells, proteins perform many functions, including:
- Helping to break down food for energy
- Building structures
- Breaking down toxins
Proteins are made up of building blocks called amino acids. Your body can make some amino acids but not others. Proteins that you get from meat and other animal products contain all the amino acids you need. These include both those your body can make and those it can't. Proteins from meat and other animal products are known as complete protein.
Proteins from plant products are incomplete proteins. That means that the proteins from one plant product don't contain all the amino acids your body needs. But another plant product may have the amino acids that the first one is missing. To get complete protein from plants, you need to eat a variety of plant foods. For instance, eating rice with beans or peanut butter with bread will give you complete protein.
You may have seen ads for protein powders and shakes that say their products contain amino acids that your body can't make. Although this is true, most people can get all the protein they need from food and don't need protein supplements.
Good sources of protein include:
- Fish and shellfish
- Red meat (beef, pork, lamb)
- Peanut butter
- Nut butters
- Soy products (tofu, tempeh, vegetarian burgers)
- Milk products (cheese, cottage cheese, yogurt)
Explore other publications and websites
Protein — On this website you will find information about protein, what foods have protein, and what happens when we eat more protein than we need.
Protein in Diet — This brief publication discusses the function of protein in your diet and how much you should consume each day.
Protein: Moving Closer to Center Stage (Copyright © Harvard School of Public Health) — This fact sheet explains what protein is, how much you should eat, the link between protein and chronic disease, soy, and much more.
Connect with other organizations
American Dietetic Association
Division of Nutrition, Physical Activity and Obesity, CDC
Food and Nutrition Information Center, USDA
International Food Information Council Foundation
Content last updated June 17, 2008.
Resources last updated June 17, 2008.
A federal government website managed by the Office on Women's Health in the Office of the Assistant Secretary for Health at the U.S. Department of Health and Human Services.
200 Independence Avenue, S.W. • Washington, DC 20201