Experts explain what happens when you eat more than your muscles need.

This article is based on reporting that features expert sources including Erin Coates, RD ; Lora Edwards, RD; Chad Kerksick, PhD; Katie Kissane, RD; Donald K. Layman, PhD; Colin Wilborn, PhD U.S. News & World Report How Much Protein Do I Need? More WHETHER YOU'RE TRYING to lose weight, gain muscle or stay strong and healthy as you age, protein is vital.

Protein is one of three macronutrients – along with carbohydrates and fat – that your body needs to build and repair tissue, form muscle and transport nutrients, says Erin Coates, a registered dietitian with Cleveland Clinic Wellness. Together, these macronutrients “are the building blocks of nutrition,” she says.

Registered dietitian Lora Edwards agrees, adding that protein is essential not just for our muscles, but also to develop and maintain healthy bones, skin and hair. She's a senior clinical nutrition specialist at the Sports Medicine Center at Children's Mercy Hospital in Kansas City, Missouri. "It's also vital for our immunity and even makes up the hemoglobin that carries oxygen in your blood," Edwards says. Consuming enough protein is particularly important for older people, research suggests. Older adults who didn't get enough protein "had significantly more functional limitations across all age groups," according to a study of 11,680 people between ages 51 and up that was published online in February 2019 in the Journal of Nutrition, Health & Aging. The importance of getting enough protein is clear. But how much protein is enough versus too much? The current recommended daily allowance for adults is 0.8 grams per kilogram of an individual's body mass (or 0.36 grams per pound of body weight). However, over the past decade, researchers found that increasing protein intake is safe and can help minimize muscle loss when cutting calories while dieting, says Chad Kerksick, director of the Exercise and Performance Nutrition Laboratory at Lindenwood University in St. Charles, Missouri. [ SEE: 5 Unintended Consequences of Eating Too Much Protein. ]


In 2015, a comprehensive review in Applied Physiology, Nutrition, and Metabolism concluded that consuming 25 to 35 grams of protein per meal was sufficient for most adults. However, some people, especially those trying to lose weight or gain muscle, as well as older adults, likely need more protein. The review found that for people trying to lose a substantial amount of weight, diets that included roughly 25% of their daily calories from protein helped prevent muscle loss and weight regain. For a person eating 1,600 calories per day, that would equal 100 daily grams of protein. The latest broad sports nutrition review that studied protein needs, published in 2018 in the Journal of the International Society of Sports Nutrition, concluded that, at a minimum, people need to double the recommended daily allowance to effectively build muscle. People who are trying to build muscle mass or who want to lose body fat should minimally eat about 1.6 grams of protein per kilogram of body weight. For a 150-pound person (who weighs 66.6 kilograms), that would equal 106 grams of protein daily, says Colin Wilborn, the executive dean for the Mayborn College of Health Sciences at the University of Mary Hardin-Baylor in Belton, Texas. Wilborn is a co-author of the 2018 sports nutrition review.