How Does Eating Protein Help You Build Muscle?

 

Your body depends on a steady supply of protein to perform critical processes that keep you alive and healthy. Proteins are involved in nearly every cellular function, and are necessary for immune regulation, hormone production, growth, and more. 

Proteins are the primary component of skeletal muscle, making up 80% of muscle mass. In order to maintain healthy muscle mass and support muscle growth, you must consume a protein-rich diet. Studies show that taking in more protein than the current recommended dietary allowance (RDA) can help people build muscle mass and preserve muscle mass during weight loss.¹

Here’s what you need to know about eating protein for muscle gains, including why protein is important for muscle growth and tips for increasing your protein intake to help build muscle.

Why Does Protein Matter for Muscle Growth?

Protein provides your body with amino acids, which are known as the “building blocks” of proteins. When you eat food with protein, your body breaks the proteins into amino acids, which are used to build new proteins and other important compounds such as neurotransmitters.²

Certain amino acids are critical for increasing muscle mass. For example, valine, leucine, and isoleucine, which are collectively known as branched-chain amino acids, are especially important for muscle maintenance and growth. 

Your body depends on a consistent intake of of amino acids through protein-rich foods  to maintain its muscle mass and prevent muscle breakdown. People who want to build muscle require more protein than people who are maintaining their muscle mass. 

Muscle hypertrophy, which is the enlargement of muscle mass, can only occur when there’s a positive net protein balance, meaning the building of new muscle exceeds muscle breakdown.³

In contrast, muscle atrophy, or deterioration, occurs when there’s a negative protein balance, which can occur when following a diet that doesn’t contain adequate protein.  

Following a high-protein diet and participating in resistance training is effective for preventing muscle loss and promoting muscle gain.  

How Much Exercise Do I Need?

How Much Protein Do You Need Per Day?

You need to consume protein every day in order to meet your body’s requirements. The Recommended Dietary Allowance (RDA) for protein is currently set at 0.8 grams per kg (g/kg) of body weight (0.36 grams of protein per pound (g/lb). While the RDA is often thought of as the “ideal” protein intake recommendation, it’s actually the minimum amount of protein necessary to prevent muscle loss and meet the body’s amino acid requirements.⁴

Though taking in the RDA may help sedentary people maintain their muscle mass, it’s not enough to meet the needs of active individuals and those who want to pack on extra muscle.

In fact, research suggests that physically active people, such as those who regularly exercise, should take in between 1.2-2.0 grams per kilogram (g/kg) of protein per day (0.54-0.9 grams per pound (g/lb) to maintain healthy muscle mass.⁴

However, people who are actively trying to build muscle mass need even more protein. 

What Are Fast-Twitch Muscle Fibers?

How Much Protein Do You Need to Build Muscle?

While people who are physically active need to take in more protein than the current RDA to maintain their muscle mass, people who want to put on muscle have even higher protein requirements. Experts suggest that people who are trying to build muscle may need to take in more than 2.0 g/kg of protein per day (0.9 g/lb).⁵

For example, people who are trying to maximize muscle growth by pairing increased protein intake with resistance exercise should aim to take in between 1.6 to 2.2 g/kg (0.72 to 1 g/lb) of protein per day.⁶

People who are trying to maintain or build muscle while also losing body fat have even higher protein needs, with some experts recommending between 2.3 and 3.1 g/kg (1 to 1.4 g/lb) of protein per day. 

Eating more protein-rich foods and adding a source of protein to every meal and snack can help you boost your overall protein intake. 

Though specific protein-rich foods as well as certain amino acids have been shown to be especially effective for supporting muscle growth, most experts agree that your total protein intake is what matters most for muscle growth.

Animal proteins are categorized as “complete” proteins, meaning they deliver all nine of the essential amino acids your body needs to function, while most plant-based proteins are “incomplete” because they’re missing or low in one or more essential amino acids. This is why plant-based proteins are known to have lower muscle -building potential than animal-based proteins. Additionally, plant-based foods generally contain less total protein per serving compared to animal foods and have lower digestibility, which is why animal proteins are generally thought to be superior for muscle protein synthesis.⁷⁸

That said, it’s entirely possible to build muscle on a plant-based diet as long as a variety of plant-based proteins are consumed and appropriate supplementation is maintained.⁹

Good Sources of Protein

Whether you’re following an omnivorous or plant-based diet, there are plenty of protein-rich foods to enjoy. Here are some of the best sources of protein you can eat:

Animal Proteins

• Eggs: 6.28 g per large egg¹⁰
• Chicken breast: 31 g per small skinless chicken breast ¹¹
• Canned salmon: 19.6 g per three-ounce serving¹²
• Whey protein isolate: 25 g per ounce ¹³
• Cottage cheese: 23.5 g per cup¹⁴
• Shrimp: 20.4g per three-ounce serving ¹⁵
• Greek yogurt: 19.9 g per seven-ounce serving ¹⁶

Plant-Based Proteins

• Tofu: 8.67 g per three-ounce serving¹⁷
• Hemp seeds: 9.48 g per ounce¹⁸
• Pea protein: 24 g per ounce¹⁹
• Edamame: 18.5 g per cup²⁰
• Tempeh: 19.9 g per 100g serving ²¹
• Lentils: 17.9 g per cup²²

Consuming a varied diet that contains both plant and animal proteins is generally recommended, but following a plant-based diet has been linked with a number of health benefits, including lower rates of heart disease and certain cancers.

However, if you’re following a vegetarian or vegan diet, it’s important to include a variety of protein sources to ensure you’re meeting your daily protein requirements.

Tips for Consuming Protein for Muscle Growth

If your goal is to gain muscle mass, there are a few evidence-based tips you should follow. 

For people who want to maintain their body weight while putting on muscle mass, experts recommend a daily protein intake between 1.6 to 2.2 g/kg (0.72 to 1 g/lb).⁶

People who are actively trying to lose weight while maintaining or gaining muscle mass have even higher daily protein needs of between 2.3 and 3.1 g/kg (1 to 1.4 g/lb), as energy restriction increases the risk of losing muscle mass.⁶

Some experts recommend spacing protein-rich meals at least three hours apart in order to best stimulate muscle growth. Additionally, though total protein intake is most important, recent research suggests that supplementing with protein after resistance training may be most effective for supporting muscle gains.²³

Most experts recommend taking in around 20 g of high-quality protein, such as whey protein, after resistance exercise to maximize muscle growth. 

Drinking a protein shake or having a protein-rich snack or meal that provides around 20 g of protein after a workout may help you reach your body composition goals.

Can You Have Too Much Protein?

Though it was once thought that high-protein diets are harmful for the kidneys, heart, and bones, research shows that healthy high-protein diets are generally safe for most people. 

In fact, diets that provide more than four times the RDA for protein have been shown to be safe for physically active people. Though more research is needed, there’s currently no evidence that high-protein diets are harmful to your health.²⁴²⁵

In fact, high-protein diets have been shown to have benefits for body composition, bone health, and heart health.

That said, diets high in specific types of protein may negatively impact health and increase disease risk. For example, diets high in red and processed meat have been linked to colon cancer, heart disease, and several other health risks.²⁶

Additionally, though high protein diets aren’t dangerous for people with normal kidney function, they could accelerate kidney function decline in people with kidney disease.²⁷

While well-rounded high-protein diets are safe for most healthy people, it’s important to understand that your protein needs depend on multiple factors, such as your body weight, age, and activity levels, which is why it’s best to base your protein intake on your specific needs and health goals. For example, while 1.2 to 2 g/kg (0.54 to 0.9 g/pound) of protein per day is likely sufficient for physically active people looking to maintain their muscle mass, protein needs may far exceed 2 g/kg (0.9g/lb) in athletes and people who want to put on muscle mass while losing body body fat. 

If you’re not sure how much protein you should be eating per day and how much protein you need to meet your body composition goals, a knowledgeable healthcare provider, like a registered dietitian, can help design a high-protein diet specific to your needs and goals. 

Other Factors for Building Muscle

In addition to increasing your protein intake, adding strength training to your wellness routine is important for building muscle mass. 

Studies show that resistance training increases muscle protein turnover and stimulates muscle protein synthesis. However, to prevent muscle breakdown and promote muscle protein synthesis after strength training, you must maintain a positive net protein balance by providing your body with protein-rich foods.²⁸

If you add in resistance training without taking in sufficient protein, you won’t reach your body composition goals. This is why combining consistent resistance exercise with a higher protein intake is so important  for building muscle mass.

A 2023 study that included 40 healthy older ex-military males found that those who participated in three weekly strength training sessions paired with a 1.6 g/kg per day high-protein diet gained significantly more muscle mass and muscle strength compared to men who participated in the same strength training regimen while following a diet that provided only 0.8 g/kg of protein per day.²⁹

If you’re new to strength training, try incorporating a couple of shorter strenght trining sessions in your weekly workout routine. Once you become stronger, you can increase your workout time and intensity.

A Quick Review

If you’re interested in gaining muscle mass, increasing your protein intake can help you reach your body composition goals. 

Studies show that taking in more protein than the current RDA is an effective way to promote muscle mass gain, especially when paired with resistance exercise. 

While high-protein diets are considered safe for most healthy people, protein needs vary considerably based on factors like activity levels and body size. Because everyone has different protein needs,  it’s important to design a diet that provides an appropriate amount of protein for your specific needs and health goals.