How much protein you need to build muscle can depend on your weight, activity level, and age. Eating too much may have some risks.
- Protein is essential for building muscle, but health experts warn eating too much can pose health risks.
- The current recommended dietary allowance (RDA) is 0.8 grams of protein per kilogram of body weight.
- Endurance or strength athletes should take 1.2 to 2 grams of protein per kilogram of body weight daily.
Protein may be a buzzword in wellness and bodybuilding, but it’s also essential. So, in some ways, one nutrition expert doesn’t mind that people are paying attention to grams of protein on nutrition labels.
“Protein is the building block for muscles,” said Dr. Anupama Chawla, director of the Division of Pediatric Gastroenterology and Nutrition at Stony Brook Children’s Hospital.
As you might expect, consuming more protein than you take in helps build muscle. And that’s part of the reason why people are honing in on the nutrient when purchasing food.
“It has become a fad because of the significant [focus] on weight loss and muscle building,” Chawla said. “It’s become an ‘in thing’ where everybody is reading the protein content.”
Though Chawla is happy protein is getting attention because of its importance to the human diet, she cautions against going to extremes, such as consuming an all-meat diet.
Too little is not good, and too much is not good,” Chawla said.
How much should you be consuming? That depends. Here’s what the research, health experts, and guidelines say.
“This means a person weighing 140 pounds only needs 51 grams of protein per day and another person weighing 200 pounds only needs 73 grams of protein per day, which is much less than “we are led to believe” by social media,” said Dana Ellis Hunnes, PhD, a senior dietitian with UCLA Medical Center.
Trista Best, a registered dietitian at Balance One Supplements, adds that this number equates to about 10 to 35% of our daily recommended caloric intake.
Age affects how much protein you need
But, as with many aspects of medicine, there’s room for nuance. For example, age is one reason to up the protein intake.
“Older adults [around ages 65 to 70] should eat a little more, roughly 1 gram per kilogram or -.45 gram per pound of body weight because they don’t absorb quite as well and are more prone to muscle loss and bone fractures,” Hunnes said.
Physical activity may require more protein per day
Some athletes also may require more to support their training regimen and physical activity.
A 2016 position statement from the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine recommended the following guidelines for protein intake among physically active individuals:
- Physically active people take in 1.2 to 2 grams of protein per kilogram of body weight or 0.5 to 0.9 grams per pound of body weight, whether they are endurance or strength athletes.
- Whether protein is consumed on the high or low end of these recommended amounts should be based on intensity of exercise or calorie restriction.
- Athletes should consume 0.25 to 0.3 grams of protein per kilogram of body weight no more than two hours post-exercise to increase muscle.
Chawla noted that athletes who consume 2 grams of protein per kilogram of body weight should do so under the guidance of a medical professional to ensure the body, particularly the kidneys, continues to function optimally.
“This is because the kidneys have to work harder to eliminate the waste by-products from protein metabolism,” said Kimberley Rose-Francis, a registered dietitian nutritionist in Southern Florida.
Hunnes added that consuming the lower end of the position’s statement, no more than 1.3 grams per kilogram per day.
“We can only absorb and utilize a certain amount of protein at any time,” Hunnes said.
“More than that just turns into excess calories and eventually into fat. So, if we take in more than we need, we cannot use it, and it either goes to waste in our urine or becomes fat if we eat too many calories overall.”
Rose-Flores noted that consuming too much protein — over 2 grams per kilogram of body weight per day — may come with risks, such as:
However, as Rose-Francis pointed out, a high protein diet was classified as 1.07–1.60 grams of protein per kilogram of body weight, not 2 grams.
Additionally, Best noted that people consuming too much protein for their weight and activity level may experience the following:
“The best, or healthiest, sources of protein are those from lean animal meats or plants,” Best said. These include:
- poultry (3 oz. of turkey contains about
25 grams of protein)
- fish ( 3 oz. of salmon contains about
22 grams of protein)
- eggs (one large hardboiled egg contains about
6 grams of protein)
“There are 20 amino acids, nine of which are essential, meaning they are required to be taken in through the diet because the body cannot make them,” Best said.
“Animal proteins have these nine already, which makes them complete proteins. However, not all plant sources are complete proteins.”
That doesn’t mean they aren’t beneficial or that you need to consume animal-based proteins to get adequate amounts to build or maintain muscle and overall health. You may just need to combine several sources of protein to keep the necessary amount.
“This sometimes means you’ll have to combine plant foods to get all nine essential amino acids. For instance, rice and beans combine to make a complete protein while quinoa is a complete protein in itself,” Best said.
What about all those protein bars and powders? Chawla isn’t a fan of the former.
“Some of these bars have 20 to 30 grams of sugar,” she said..
Chawla is more amenable to powders, particularly whey, for athletes needing more protein. But she cautions that everyone should refrain from being hyper-focused on protein for strength and overall health.
“People get stuck on protein sources and forget that they are not getting adequate calories from other sources,” she said, such as complex carbohydrates and produce.
A 2022 meta-analysis of 69 studies suggested sticking to the lower end of the position statement’s recommendations.
Based on previous research, authors indicated that eating 1.5 grams of protein per kilogram of body weight, which equates to 0.7 grams of protein per pound, should be enough to build strength when combined with resistance training. The point about resistance training is a reminder that muscle mass is not simply a product of protein intake.
“If someone wants to build more muscle, they need to up the intensity of their strength training — higher weights, higher reps, or both — and break down their muscle fibers. Then, they need to eat a healthy diet,” Hunnes said.
They consumed less than 20 grams of protein per meal, and the majority of protein came from plant-based sources.
In addition, a
A 2020 systemic review and meta-analysis of previous randomized control trials indicated that upping daily protein intake by up to 3.5 grams per kilogram of body weight over the course of several meals could help people grow or maintain muscle mass.
Chances are, if you live in the United States, you’re getting enough protein.
“If you’re eating a fairly varied diet, and you’re getting enough calories in this country — and you don’t have medical conditions such as protein-losing enteropathy or liver failure — you’re almost definitely getting enough protein,” Hunnes said.
What are the signs that you aren’t getting enough?
“An inadequate [amount of] protein can result in a weakened immune system, malnutrition, edema due to fluid imbalance, hair thinning, and muscle loss are some long-term complications resulting from inadequate protein intake,” Rose-Francis said.