Protein makes its way in and out of the news often, from high-protein/low-carb diet fads to the addition of protein in food products like sports bars and ice cream. Consumers can be left wondering how much protein they truly need.
The 2015 Dietary Guidelines for Americans recommend eating a variety of protein-rich foods, including lean meats and poultry, seafood, eggs, beans, peas, nuts, seeds, and soy products. Some dairy products, such as Greek yogurt and cottage cheese, are also good sources of protein. Whole grains, whole-grain products, and vegetables all contain some protein.
It is recommended that healthy adults consume 0.8 grams of protein per kilogram of body weight per day. Protein needs increase during periods of growth, pregnancy or lactation, infection, and injury such as trauma or surgery. Athletes in particular need more protein for muscle growth and repair. Depending on the type of training, needs range from 1.2 – 2 grams of protein per kilogram of body weight per day. Eating high-quality protein within two hours after exercise can help with this process.
Plant proteins are generally less digestible than animal proteins, which can be a concern for vegetarians. However, if vegetarians have a varied diet, that includes beans, legumes, nuts, seeds, whole grains, and colorful fruits and vegetables, they will likely get enough total protein
The recommended upper limit of protein intake is 30-35 percent of total calories in the diet; however, research is unclear as to how much protein should make up a single meal. Some research indicates that the body can only make use of a certain amount of protein at a time— about 20-30 grams—to build muscles. Other studies do not support a practical upper limit to protein intake at a meal. It appears the difference in these conclusions is due to what foods were eaten at meals, sources of protein, and desired outcome of protein intake. Specifically for muscle building, 30 grams at a time appears beneficial.
Note that exceedingly high-protein diets can harm overall health. Elevated protein levels can cause dehydration, kidney damage, and bone and calcium imbalance. It is recommended to limit red meat such as beef, pork, and lamb to 12-18 ounces (cooked) per week. Avoid processed meat such as bacon, sausage, ham, hot dogs, and other deli meats due to their link to stomach and colorectal cancers.
Overall, protein is an essential part of our diet, and choosing plant-based and/or lean animal proteins will help keep the body healthy. Protein-rich foods should be paired with a variety of fresh fruits and vegetables as well as a small portion of whole grains for optimal meal structure. It is best to spread protein intake throughout the day to ensure all meals are complete and balanced.
For a chart of healthy protein choices, click here.
Rebecca Guterman, MS, RD, CDN, is the Senior Dietitian at Mount Sinai’s Derald H. Ruttenberg Treatment Center which offers a wide range of outpatient services for all cancer diagnoses, with the exception of breast cancer.
What Does Protein Do?
Protein plays a role in many body functions. It helps cells communicate within our body, moves compounds through the blood, plays a role in energy metabolism, and helps with muscle contractions and building. Proteins such as collagen, elastin, and keratin are found in the bones, teeth, skin, tendons, cartilage, hair, and nails. Other proteins provide the body with protection against bacteria or viruses. Minerals such as copper, iron, and zinc are stored in body tissues bound to proteins.
