With the increasing popularity of protein bars, protein powders and high-protein meals, you may be wondering if you're getting enough protein in your diet. But in fact, most Americans are actually getting about twice the amount of recommended protein per day. While some populations, such as athletes and the elderly, might benefit from high-protein diets, most people would find it best to make leaner and more varied protein choices.
What Is Protein?
Proteins are organic compounds made up of amino acids. Every cell, tissue and organ contains protein, which helps build, maintain and repair body tissue. Protein is also found in the diet, from both animal and plant sources. The protein you eat provides your body with the energy and nutrients it needs to make new proteins.
Types of Protein
Dietary proteins can be either complete or incomplete. Complete proteins contain all the essential amino acids necessary to make new proteins. Essential amino acids cannot be made by the body and must be obtained from the diet. In contrast, nonessential amino acids can be made by the body and do not need to be obtained from food. Animal-based sources are complete proteins, while plant-based sources, except for soy products, are incomplete proteins.
Healthy Protein Choices
When choosing either animal- or plant-based proteins, it is important to consider the overall quality of the protein. Animal sources of protein can be high in saturated fat. Healthy animal-based proteins are lean meats like poultry without the skin, as well as seafood, eggs and low or non-fat dairy products. Most plant-based sources of protein contain only healthy fats, along with fiber, vitamins and minerals. Despite the fact that nearly all plant proteins are incomplete, you can still manage to get all the needed amino acids by eating a variety of plant sources. Good sources of plant proteins are legumes, tofu and other soybean products, nuts, seeds and grains.
Recommended Amounts
According to the Institute of Medicine, the average healthy adult requires 0.36 g of protein per pound of body weight per day. So for example, if you weigh 150 lbs., you would need 54 g of protein a day. In food terms, that would equal a 4 oz. piece of chicken, 6 oz. cup of Greek yogurt and a half-cup of skim milk.
Athletes and Older Adults
Athletes and people over the age of 60 might benefit from increasing the recommended amount of protein in their diets to support muscle growth and prevent muscle loss, respectively. The recommended amount of protein for strength and endurance athletes ranges from 0.5 to 0.8 g of protein per pound. Older adults may benefit from increasing the amount of protein in their diets to 0.5 g of protein per pound per day.
References
- Centers for Disease Control and Prevention: Nutrition for Everyone -- Protein
- Harvard School of Public Health: The Nutrition Source -- Protein: Moving Closer to Center Stage
- Institute of Medicine; Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids; September 2002
- "Medicine and Science in Sports and Exercise"; American College of Sports Medicine Position Stand. Nutrition and Athletic Performance; American Dietetic Association, et al.; March 2009
- "Journal of the American College of Nutrition"; Protein and Older Adults; Ronni Chernoff, Ph.D., R.D.; December 2004
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