American diets go through waves of popularity. One year fat is unfathomable and the next year the trend is to “skip the carbs.” Protein intake is currently in vogue, but how much do we really need to eat in a day?
Bonnie Jortberg, PhD, RDN, CDCES, a nutritional scientist and associate professor of family medicine at the University of Colorado School of Medicine, busts the myth that Americans aren’t getting enough protein. In general, she said, Americans get much more protein than they need in their diets.
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“For the majority of adult Americans, you want 0.8 grams of protein per kilogram of body weight per day, which equates to about 56 grams of protein a day for the average man and about 46 grams of protein a day for the average woman,” Jortberg said.
For context, a chicken breast has about 43 grams of protein. The only people Jortberg sees with severe protein deficiencies are those on very strict, obscure diets or those with disordered eating.
The protein wave does have some evidence behind it as far as weight loss or maintenance, Jortberg said. “Some weight-loss studies show that if people are eating a higher protein diet they tend to feel fuller and more satiated,” she said. “And then if people feel that way, they don't eat as much, and they can lose more weight.”
Who should supplement protein intake?
“If people are eating a varied diet, they will have no problem getting enough protein,” Jortberg said. In that case, she would not recommend supplementing with protein bars and powders on a regular basis. However, depending on the protein bar (some are little more than glorified candy bars), there’s no need to clear the products from the pantry, Jortberg said.
Generally, only the most elite weight-lifters need to worry about increasing their protein intake, Jortberg said. “There is evidence that eating a higher protein diet and doing intensive weightlifting will help build more muscle.” But for the average, active adult, the best way to build muscle is to just be physically active, she said.
Another population that could potentially benefit from extra protein are people 65 and older to help reduce their loss in muscle mass, Jortberg said. “There are some newer studies that show that older adults’ protein needs may go up a little bit because you’re unfortunately losing muscle mass at that age.” However, the recommendations haven’t been updated yet, she said.
The best sources of protein
Too much protein can also be harmful, Jortberg said. “Most high-protein sources are also high in fat and particularly saturated fat. Your red meats are a good example.”
The best sources of protein are leaner meats, such as chicken and fish, as well as eggs and low-fat dairy. Other plant sources include quinoa, beans and legumes, she said.
For most people, the Mediterranean diet provides a good mix of lean proteins and other nutrients, Jortberg said. “It’s very high in fruits and vegetables, but also includes lean proteins, whole grains, nuts, seeds, your healthier kinds of fats and is very moderate in protein. If you look at very good research, the Mediterranean-type diet is really what most of us should really be striving toward.”