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Muscle is made up of mostly protein, so it’s no surprise that a high-protein diet can help you build more of it.
Exactly how much protein per day you need is debatable. Common bodybuilding advice suggests eating one gram of protein per pound of bodyweight to support muscle growth, however, the science behind this recommendation varies depending on age, fitness level, and overall body composition goals.
Based on the existing research, here’s how much protein you should be eating to build muscle.
Calculate Your Protein Needs
Get your ideal daily protein needs for weight loss or muscle gain in just a few minutes with this simple protein calculator.
How High Protein Intake Supports Your Muscles
Protein is made up of amino acids that act as building blocks for your body’s cells and tissues, including muscle mass. This essentially means, your muscle is made up of protein.
These amino acids are essential for supporting numerous bodily functions. If you aren’t getting the required nutrients - like essential amino acids - through food, your body doesn’t have what it needs and has to compromise.
This involves stealing amino acids that are stored in your body (in your blood and muscle tissue) which can lead to muscle loss over time.
Muscle Protein Synthesis (MPS) vs. Muscle Protein Breakdown (MPB)
Amino acids are also used for muscle protein synthesis (MPS) - the process of repairing, maintaining, and growing muscles after intense use.
When muscles are used during exercise or strenuous activity, it creates micro-tears and leads to muscle protein breakdown (MPB). Amino acids are then shuttled to your muscles to repair this damage and synthesize new tissue to replace the damaged ones.
This process doesn't automatically lead to bigger muscles (there is a little more needed for that), but it can make your muscles stronger or adapt to the type of training that caused the tears in the first place (1).
MPS is why protein, and regular strength training, in particular, are so essential for maintaining and building lean body mass.
Muscle Growth
When it comes to building muscle mass, your protein intake is a considerable factor.
With the role of amino acids in muscle protein synthesis, maintaining a positive protein balance - in other words, eating more protein than you are breaking down or using, is one part of the muscle-building equation.
Muscle growth occurs when muscle protein synthesis exceeds muscle protein breakdown.
This can be achieved through a combination of increased protein intake, a strategic strength training routine (studies suggest a minimum of twice per week), adequate rest (this is when MPS occurs), and often plenty of calories to support weight gain overall (bulking diet).
Depending on individual factors like fitness level and starting body composition, it is possible to lose weight or fat while building muscle simultaneously, but this is not ideal for everyone and your rate of muscle growth is significantly less than following a standard weight gain approach.
How Much Protein Do You Need to Gain Muscle?
So how much protein do you need to put on muscle? Your protein needs are directly related to your muscle mass - the more you have and the more you use it, the more protein you need.
This is true to both preserve lean body mass and increase muscle mass.
Age and activity level also impact how much protein is required to promote muscle growth.
Bodybuilders and weightlifters have higher protein needs because they are looking to add mass and are simultaneously using their muscles more than the average person or non-lifter.
Of course, it is entirely possible to overdo it. Eating too much protein can negatively impact your ability to build muscle by limiting your intake of other important macros for bulking (healthy fats and carbohydrates) that support your training and weight gain.
So getting your daily protein intake right for your individual requirements is crucial to getting the best results.
Many fitness enthusiasts recommend about one gram of protein per pound of body weight for building muscle, but this high protein intake likely isn’t a perfect approach for everyone and the research varies on this topic depending on age, fitness level, and overall body composition goals (2,3,4,5,6,7,8,9).
What the Science Says
Some older studies suggest that an intake of at least 1.6 to 1.7 grams per kilogram of body weight (0.7 to 0.8 grams/pound) is needed to maintain lean mass with strength training (10,11).
More recent studies suggest intakes as high as 1.8 to 2.0 grams per kilogram of body weight (0.8 to 0.9 grams/pound) (12).
And a larger and more recent review of the research determined that for most, there aren't any beneficial effects of eating more than 1.6 grams of protein per kilogram or 0.72 grams per pound of body weight (13).
All of these recommendations fall within the range suggested by the American College of Sports Medicine which suggests 1.2 to 2.0 grams per kilogram of body weight (0.54 to 0.9 grams/pound), which would translate to 81 to 136 grams for a 150-pound adult for preserving and building muscle.
Your ideal protein needs can also depend on your overall calorie intake per day.
Your macro diet ratio may have an impact on body composition when looking at a surplus or restriction of calories. A narrative review of the research and smaller studies have suggested that higher protein intakes between 2.2 to 3.4 grams/kg (1 to 1.5 grams per pound of body weight/day) during a large calorie surplus (to promote weight gain) results in lower gains in body fat - promoting more muscle overall (14,15).
So, looks like the debate continues around how much protein is actually needed to gain more muscle and we may not get a definitive answer any time soon, due to the multitude of individual differences among us all.
The Verdict
Based on the averages from evidenced backed recommendations, a good rule of thumb for maintaining existing muscle is to eat roughly 0.8 to 1 gram of protein/pound of body weight. And this amount may increase as high as 1 to 1.5 grams/pound when looking to add lean mass using a calorie surplus.
How to Get Enough Protein for Your Body
Once you know your daily protein needs, the next step is finding the best sources of protein to eat. These include lean meats, fish, dairy, and plant-based options.
Then learn how to portion your food choices to match your macros and start tracking your daily intake to ensure you are staying consistent.
Dial in your nutrition and crush your bulking macros with this free meal prep toolkit for muscle gain. An RD-written guide complete with a macro meal planner, food lists, and expert advice to help you maximize results.
