In order to help consumers understand protein choices the Dietary Guidelines for Americans provides protein equivalents to help in meal and snack planning.
One ounce of meat is equal to: 1 egg, ¼ cup of beans, 1 tablespoon of peanut butter, 2 ounces of tofu, and a half ounce of mixed nuts. Protein is used in the body to build and repair body cells. This equivalency assumes that each of these protein foods will act the same in the body. A study in The Journal of Nutrition (Metabolic Evaluation of the Dietary Guidelines’ Ounce Equivalents of Protein Food Sources in Young Adults: A Randomized Controlled Trial | The Journal of Nutrition | Oxford Academic (oup.com) examined if these protein equivalents were equal and their results showed they were not.
Beef, pork, tofu and eggs were the most efficient in building and repairing body protein. Kidney beans, peanut butter and mixed nuts were less efficient but did result in some building and repairing of the body. These plant-based protein sources just had a smaller effect than the richer protein sources.
What does this all mean to you? The Dietary Guidelines lead one to believe that plant and animal protein sources are equivalent serving for serving, but in actuality this is not true. Though plant proteins are useful in the body, in many cases you would need to eat more of them to realize the same benefit from richer protein sources from animals or tofu. For example: the researchers found that the protein equivalent from 2 eggs would require a person to eat close to 7/8 of a cup of mixed nuts. Though the protein in these two servings if the same the calorie difference is significant; 2 large eggs equal approximately 155 calories while 7/8 cup of mixed nuts equals 525 calories.
Since obesity is a major concern in the US, the researchers felt we needed a better way to note protein sources and suggested high quality protein foods and lower quality protein foods. This is important in growth, aging, healing, and athletic performance.
