How Much Protein a Day Do You Need to Build Muscle?

• 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 Anupama Chawla, MD, a pediatric gastroenterologist at at Stony Brook Medicine.

Indeed, research from 2018 indicates that muscle protein breaks down in the human body. Consuming more protein is essential to rebuilding — and even building more — muscle.

As you might expect, consuming adequate protein in conjunction with strength training helps you build muscle. And that’s part of the reason why people are honing in on this nutrient when purchasing food.

“It has become a fad because of the significant [focus] on weight loss and muscle building,” Chawla told Healthline. “It’s become an ‘in thing’ where everybody is reading the protein content.”

But pump the breaks before pouring an entire tub of protein powder into tomorrow morning’s breakfast smoothie. Experts and research indicate that there is such a thing as too much protein.

Though Chawla is glad protein is getting attention because of its importance to the human diet, she cautioned 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.

“A person weighing 140 pounds needs [at least] 51 grams of protein per day, and another person weighing 200 pounds needs [at least] 73 grams of protein per day,” Dana Ellis Hunnes, PhD, a senior dietitian with UCLA Medical Center, told Healthline.

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.

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.

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,” Kimberley Rose-Francis, a registered dietitian nutritionist in Southern Florida, told Healthline.

Hunnes recommended consuming no more than 1.3 grams of protein per kilogram of body weight daily.

When you consume more protein than needed, your body may store the excess calories as fat.

Rose-Francis noted that consuming too much protein — over 2 grams per kilogram of body weight daily — may come with risks, such as un unwanted weight gain.

In addition, people living with or at risk for kidney disease may also experience azotemia (kidney malfunction).

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:

Plant-based proteins, like beans, tofu, and lentils, provide an alternative for vegetarians and vegans, but these sources are not always equivalent.

“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, noting complex carbohydrates as an adequate protein source.

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.

Another 2022 study of more than 4,800 Chinese individuals 60 and older suggested that male participants who consumed more than 78 grams per day and females who consumed 68 grams daily had the most protection against low muscle mass.

They consumed less than 20 grams of protein per meal, and the majority of protein came from plant-based sources.

In addition, a 2022 systematic review and meta-analysis of protein intake in healthy adults suggested that 1.6 grams of protein per kilogram of body weight per day could help individuals under 45 years old increase body mass slightly. People older than 45 only saw marginal increases.

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.