If you want to gain muscle, you probably already know that eating enough protein is a key part of the process. As one of our body’s three macronutrients, protein is required for building and repairing muscle tissue. But exactly how much protein should you eat to gain muscle? Is piling your plate with boiled eggs and chicken breast all it takes? (Spoiler alert: Not quite.)

We spoke with registered dietitians to learn all about protein’s role in your body, protein intakes for those with muscle-growth goals, and how that intake should change as you get older. Read on for everything fitness enthusiasts and beginners alike need to know.

Why Is Protein Crucial for Muscle Growth and Repair?

In short, protein makes it possible for your body to repair and strengthen your muscles. 

Your muscles are made up of tiny fibers, like threads in a sweater. These fibers are super strong, but when they undergo stress during activities like weight lifting or resistance training, tiny tears can occur in the muscle fibers.

This is a normal and important part of building stronger muscles. When these micro tears happen, your body goes into repair mode to repair them. That's where protein comes in. In a process called muscle protein synthesis (MPS), the amino acids from protein help fix and “fill in” these little tears, which can make your muscles bigger than before when paired with exercise.

Protein’s role doesn’t start and end at muscle growth or recovery, either. The macronutrient is crucial for supporting other physiological functions in your body, including enzyme production, blood sugar stabilization, immune function, and more. 

How Much Protein Should You Eat to Gain Muscle?

To build muscle, aim to eat 1.4–2.2 grams of protein per kilogram of body weight each day, says Cynthia Sass, RD, a registered dietitian and board-certified specialist in sports dietetics. (To calculate your approximate weight in kilograms, divide your weight in pounds by 2.2.)

If this protein intake recommendation seems higher than you’d think, it might be because, well, it is. “The Recommended Dietary Allowance (RDA) for protein is only 0.8 grams per kilogram of body weight, but this is a recommendation for the general (sedentary) population and should be considered a minimum,” says registered dietitian Ellen Landes, RDN, owner of The Runner's Dietitian. “Active people need more than this, especially if the goal is to build muscle.”

For example, a 150-pound person living an inactive lifestyle would likely need about 55 grams of protein a day, Sass says. But if that same person was doing regular cardio and strength training workouts to build muscle, their protein needs would go up to about 150 grams per day, she explains. 

Your protein needs will also go up as you age (more on that below) or during pregnancy.

Is There Such a Thing as Too Much Protein?

Most athletes and active people rarely need more than 2.2 grams of protein per kilogram of body weight per day. (Some experts, such as the Mayo Clinic, cap that number even smaller at 2 grams of protein per kilogram of body weight.) That’s because there’s a limit to how much dietary protein can be used for muscle maintenance, healing, and repair. 

“Consuming more protein than your body needs to perform these jobs can crowd out the other two macronutrients: fat and carbohydrates,” Sass says. “An imbalanced macro ratio can lead to unwanted issues; too little fat can impact hormone balance and limit the absorption of fat-soluble vitamins, and too little carbohydrates can lead to a lack of fiber, negative changes to the gut microbiome, and various nutrient deficiencies.”

In addition to excess protein not being used efficiently in the body, too much of the macro may impose a metabolic burden on the bones, kidneys, and liver, according to a 2013 review published in ISRN Nutrition. What’s more, researchers found that high-protein, high-meat diets may be associated with an increased risk of heart disease or cancer due to the saturated fat and cholesterol intakes that come with those diets, though more research is needed.

How Much Protein Should You Eat After Working Out?

Consuming protein after a workout can support muscle repair and growth. While there isn’t a one-size-fits-all answer, aim to eat about 20-40 grams of protein after exercising, Landes suggests. “This range is ideal for stimulating muscle protein synthesis to repair and build muscles after exercise,” she explains. 

While there’s no bad time to eat protein, some experts recommend having your post-exercise meal or snack within an hour after your workout. This is because your muscles are thought to be better optimized to use the food you eat to rebuild and recover during this “anabolic window.”

Something else to remember: “As we age, we need more protein to kickstart [muscle protein synthesis], so people over 40 should aim to hit that 40-gram goal after a workout,” Landes says.

Some research supports this higher post-workout protein intake. A small 2016 Physiological Reports study on young, resistance-trained men suggests that a 40-gram dose of protein immediately after exercising stimulated muscle protein synthesis to a greater extent than a 20-gram dose.

With all these general guidelines in mind, don’t worry too much about tracking the exact amount of protein (or other nutrients) you get. For some, counting macros can be harmful, which is why, in many cases, experts advise focusing on a well-rounded diet instead. That said, if you’re hoping to track your protein intake for a specific muscle growth goal (or another health goal), it’s a good idea to work with a registered dietitian who can help you get started and determine the best amount of protein for you.

How Do Different Types of Protein Support Muscle Growth?

Not all protein sources deliver the exact same nutritional benefits. “Complete proteins like meat, fish, dairy, and soy contain all essential amino acids and are particularly rich in leucine, which is an important amino acid that kickstarts muscle protein synthesis,” Landes says.

Plant-based protein sources are excellent too, but it’s important to be mindful of leucine, especially after a workout, as it’s less concentrated in plant-based options. But so long as you eat enough total protein from an array of plant sources, experts say you’ll satisfy all your amino acid needs.

And “if you’re using a plant-based protein powder, I recommend looking for one that combines multiple sources of plant protein, such as pea and rice protein, rather than just one or the other,” Landes says. “This can help make the amino acid profile more robust.” (It can help to select a protein powder from the National Sanitation Foundation’s (NSF) Certified for Sport® directory if you want to use one. Remember, it’s also smart to get your healthcare provider's approval before trying any new supplements.)

Should Protein Intake Change as You Age?

As you get older, your body undergoes various changes, including a gradual decline in muscle mass. Adequate protein intake becomes increasingly important to combat muscle loss and maintain overall health. Older adults may benefit from a slightly higher protein intake to support muscle preservation and prevent age-related declines in strength. 

“Sedentary protein needs increase from 0.8 grams per kilogram [of body weight per day] to 1–1.2 grams per kilogram at the age of 65. That increase is to help prevent age-related muscle loss,” Sass says. “For building muscle, the same goals apply; generally, increasing protein intake to 1.6–2.4 grams per kilogram, depending on an individual’s exercise program.”

More Nutrition Tips for Muscle Growth

Eating more protein shouldn’t be the only thing on your radar when you’re building muscle. Here are a few other things to consider, according to Sass:

1. Get Enough Calories

To ensure that dietary protein is used for its intended purposes and not diverted for energy, it’s crucial to meet your calorie needs. Simply hitting your protein target won't be as effective for muscle growth if you’re not getting enough overall calories. Without sufficient calories, some of the protein won't be available for its essential tasks, such as maintenance and repair, potentially hindering muscle-building efforts.

2. Eat Protein at Each Meal

In general, the body optimally utilizes protein when it's evenly spread throughout the day. For instance, if you require 100 grams of protein daily, you’d likely want to spread those 100 grams evenly across your meals, rather than trying to eat it all in one window. We can only absorb up to 40 grams of protein in one sitting, the Cleveland Clinic notes, so it won’t benefit you to eat more than that at one time.

3. Pay Attention to Leucine

Leucine, a unique essential amino acid and a building block of protein, acts as a trigger for muscle protein synthesis. Even if an athlete consumes enough protein overall, inadequate leucine could impede efficient muscle building.

So, how do you even know you’re getting enough leucine? Start by choosing the right bites, Sass suggests. Leucine-rich foods include animal proteins like beef, chicken, turkey, pork, fish, eggs, and dairy products, and plant-based sources like soybeans, tofu, tempeh, and legumes. And remember, says Sass, that spreading your protein intake out evenly throughout the day (including within your pre- and post-workout snacks) can help maximize muscle protein synthesis. 

The Takeaway

Protein is a crucial element in the journey to building muscle. Understanding your unique protein needs, choosing an array of high-quality dietary sources, and adapting intake as you age are essential components of a well-rounded fitness and nutrition plan. Remember, there's no one-size-fits-all approach, so consulting with healthcare professionals or registered dietitians ensures a personalized strategy that aligns with your health goals and overall well-being.

For personalized advice about how much protein you should eat to build muscle (plus the answers to the rest of your nutrition questions), consult with a registered dietitian. They can tailor a program based on your specific training program and goals.