How much protein do you need to gain muscle? It’s a question that’s been debated for decades, with fitness enthusiasts and experts alike offering a range of recommendations.
In this article, we provide the guidelines to help you determine the optimal amount of protein for your individual needs, all based on the latest scientific evidence.
- If you lift weights, your daily protein requirement rises. In the short term, this happens because your body needs more protein for muscle protein synthesis and to repair itself after training. In the long term, you also need more protein to maintain your larger muscle mass.
- The recommended dietary allowance (RDA) of protein is 0.8 g/kg body weight/day (g/kg/d). That’s the minimum amount of protein to maintain health and muscle mass in a non-training population.
- Training to increase your strength and muscle mass requires a daily intake of 1.6–2.2 g/kg/d to maximize your gains.
- A caloric deficit increases your protein needs further, and you can decrease your risk of muscle loss during a cut by increasing your protein intake by an additional 0.5 g/kg/d.
- You can calculate your daily protein need with our protein calculator.
If you’re looking to build muscle, one of the most important factors to consider is your protein intake. Not only does protein provide the building blocks for muscles, but your hair, skin, hormones, blood, and bones are all built from these chains of amino acids.
When you eat or drink protein, your body senses high levels of amino acids in the bloodstream. Those amino acids act as signals that initiate muscle protein synthesis (MPS), and your muscles respond by producing new muscle protein.
Muscle protein synthesis is crucial for building lean body mass and repairing muscle tissue. It plays an important role for anyone who wants results from their efforts in the gym, from young elite athletes to older adults.
Discounting genetics (most of us would like better genetics for muscle gain, but they are what they are), you have two primary ways to boost MPS:
- Resistance training. Resistance exercise increases basal MPS and elevates it further for at least 24 hours following a weight training workout.
- Eating a high-protein diet. Higher protein intakes than average mean greater muscle protein synthesis than average.
The combination of the two – the right amount of protein on a daily basis and regular strength training – is more than the sum of its parts. Protein and lifting are the best partners for optimizing muscle protein synthesis, resulting in lean muscle mass and increased muscle strength.
Let’s assume your training is on point. You follow a good training program, practice progressive overload, allow for adequate recovery, and so on.
The question then is: how much protein should you eat per day?
Let’s get into it!
How Much Protein Do You Need per Day?
How much protein you need depends on who you ask and who is asking. General guidelines for the population as a whole are lower than recommendations for athletes and bodybuilders looking to gain lean mass.
How Much Protein Does the Average Person Need?
According to guidelines from US and European authorities, the Recommended Dietary Allowance (RDA) of protein is around 0.8 grams per kilogram of body weight (0.36 grams per pound of body weight.)
That’s enough for general health and for sedentary adults to maintain muscle mass. It is far from optimal for someone looking to build muscle and strength.
Another way to calculate daily protein requirements is by energy percentage, or the Acceptable Macronutrient Distribution Range (AMDR). Generally, 10–35% of your caloric intake is recommended to come from protein. In other words, eating 2,500 calories translates into 250 to 875 calories per day from protein.
For muscle building purposes, that way of counting is far better. In the 2,500-calorie example, the upper end of the interval works out to almost 220 grams of protein per day. That’s enough protein for many bodybuilders.
Interestingly, even the lowest level of protein intake reflected in the AMDR is higher than that of the RDA.
How Much Protein Do Athletes Need?
Physical activity increases your daily protein needs.
- When you lift weights regularly, you increase the amount of protein you need to build new muscle and repair damaged muscle protein.
- If you run, bike, or engage in some other form of endurance training, you use more amino acids as energy. You need to eat more protein to give your muscles the building blocks they need to repair, replenish, and recover.
According to authorities like the American College of Sports Medicine, people with a high physical activity level should aim for a range of 1.2–1.7 grams of protein per kg (0.5 to 0.8 grams per pound) of body weight.1
That includes people who engage in strength training to build muscle and endurance athletes training for a running or biking event.
How Much Protein Do Bodybuilders and Strength Athletes Need?
Bodybuilders aren’t satisfied with maintaining muscle mass or knowing how little protein they can eat and still grow.
They want optimal gains in muscle mass. And optimal gains require an optimal protein intake.
Today, it is well-established that increasing your protein intake from an average to an optimal level can bring substantial extra gains from training.
A 2018 systematic review of 49 training studies found that increasing protein intake from 1.4 to 1.8 g/kg/d led to 27% greater muscle growth over the course of 2–3 months.2
These gains were even greater in the participants who had already been lifting for several years.
The researchers also found that the average amount of protein where even more didn’t result in additional gains was, on average, 1.6 grams per kg of body weight (0.7 grams per pound) per day.
Note: on average.
The protein intake they found sufficient for 97.5% of all the 1 863 participants in the analysis was 2.2 g/kg/d.
In other words: if you want to ensure you get enough protein to maximize muscle growth, the best way is to aim for 2.2 grams per kilogram of bodyweight per day (1 gram per pound of bodyweight.)
For a 90-kilogram (≈200-pound) bodybuilder, that translates into roughly 200 grams of protein per day, give or take.
Another study, using eight natural bodybuilders as subjects, came to similar conclusions.3
The researchers concluded that these muscular men needed at least 1.7 g/kg/d on average to avoid losing any fat-free mass. It’s safe to assume that 2.2 g/kg/d is a good idea for gaining muscle.
Worth noting is that the measurements were conducted on a rest day. Training increases your protein requirements during the following 24 hours.
- Consuming 1.6–2.2 grams of protein per kilogram of body weight per day gives your muscles the protein they need to grow. Aiming for the upper range of that interval ensures they have enough for optimal gains in muscle mass.
Let our handy protein calculator do the job for you if you want to eliminate the hassle of calculating your protein needs. Based on scientific data, it’ll crunch the numbers with a few clicks, whether you’re looking to build muscle or lose fat.
>> Protein Calculator for Weight Loss and Muscle Gain
How Much Protein Do Older Lifters Need?
As we age, our protein needs increase.
Research shows that the 0.8 g/kg/d RDA is insufficient for older adults. You need up to 1.3 grams of protein per kilogram of body weight per day to “reduce age-related muscle mass loss.”4
However, I’m sure you’re not satisfied with reducing muscle loss. You want to gain muscle, and there is no reason to let age stop you.
Because most studies look at young participants, consider aiming for the upper end of the recommended protein intake range.
- At least 2 grams of protein per kilogram (0.91 grams per pound of body weight) daily ensures enough protein to support optimal muscle growth.
>> Building Muscle After 50: The Essential Guide
>> Building Muscle as You Age: Protein Needs for the Older Lifter
>> The Best Protein Powder for Men and Women Over 50
How Much Protein Do Vegan Lifters Need?
Animal proteins generally contain more of the essential amino acids you need to build muscle than plant-based proteins.
While some vegetable proteins, like soy, buckwheat, and quinoa, are considered complete proteins, most plant sources provide too little of one or more essential amino acids.
In addition, you don’t absorb plant-based proteins as effectively as high-quality proteins from the animal kingdom.5 6 Plant-based foods contain so-called antinutrients that interfere with nutrient uptake, including protein.
Fortunately, an exclusively plant-based diet can be just as effective for building muscle as one including animal protein sources.7
You have two ways to make plant-based proteins more anabolic.
The first is to eat more of it. Up your protein intake by 25% compared to standard recommendations, and you’re golden.89
The second is to combine protein sources.
- Legumes, lentils, peas, and vegetables: combine with grains, nuts, and seeds.
- Grains, nuts, and seeds: combine with legumes.
Typically, there is no need to combine different plant proteins in a particular meal as long as you eat a varied, balanced diet. However, to optimize muscle protein synthesis for bodybuilding purposes, you could do it as a precaution.
- For vegan lifters, upping your protein intake by 25% ensures you get enough.
- Combining two incomplete proteins can make a complete protein.
How Much Protein Do You Need on a Fat-Loss Diet?
When you’re dieting for weight loss, your protein requirements go up. A calorie deficit increases your muscle breakdown and reduces muscle protein synthesis.
The good news is that you can counter this by increasing your protein intake.
Adding approximately 0.5 g protein/kg/d when in a caloric deficit will put you in the right ballpark.
The leaner you are, the more protein you need to spare your muscle mass.
For someone with plenty of body fat, 2 grams of protein per kg (0.91 grams per pound) of lean body mass (LBM) will protect your hard-earned muscle.
If you’re already relatively lean and looking to get shredded or on an aggressive cut, you can increase your protein intake to 2.3–3.1 grams per kilogram (1.04–1.4 grams per pound) of lean body mass daily.10
That’s also a good amount to aim for if your goal is to build muscle and lose fat simultaneously.
Note that your fat-free mass, not your total body weight, primarily dictates your protein need during a calorie deficit. Your body fat isn’t particularly metabolically demanding.
That means that general recommendations are not practical if you are severely overweight. You’d end up with an unrealistically high protein intake and a bland diet and maybe lose out on valuable nutrients.
A good rule of thumb is to make a general estimate of what would constitute a “normal weight” for you and calculate your protein need based on that figure.
- During a calorie deficit, your protein needs increase.
- A protein intake of at least 2 grams per kg of lean body mass helps protect your muscle during weight-loss diet.
- If you’re already relatively lean, 2.3–3.1 grams of protein per kg lean body mass is beneficial.
>> How to Cut: Lose Fat and Keep Your Muscle Mass
>> How to Cut for Bodybuilding: Top 12 Tips for Success
>> How Long to Cut for Bodybuilding
>> Macros for Cutting: Count Your Way to Fat Loss
>> How to Build Muscle and Lose Fat at the Same Time
Protein from Foods vs. Protein Supplements
No evidence exists that protein supplements help you build muscle or improve your body composition. Your total protein intake is the most critical factor, not if you get it from foods alone or a combination of food and protein supplements.
Of course, a healthy diet is essential to get all the nutrients your body needs, but for muscle-building purposes, a gram of protein is a gram of protein whether you get it from whey protein or regular dairy products.
That being said, protein supplements can be very convenient.
- A high protein diet can make you feel uncomfortably full, especially during a bulk. Adding a protein shake or two makes reaching your target daily protein intake effortless.
- After a workout, many people don’t feel like eating a full meal right away but still want protein to kick-start muscle protein synthesis. Scoop some protein powder into a shaker, add water, and you’re good to go.
Some popular protein supplements include whey, casein, soy, beef, pea, and egg protein powders. They are all excellent options for upping the protein content of your diet.
- You don’t have to use protein supplements to build muscle, but they can be convenient.
>> Whey Protein: The Complete Guide to the Most Popular Protein Supplement for Strength Athletes
>> Whey Protein Concentrate vs. Isolate: What’s The Difference?
>> Casein: Fast Gains from Slow Protein?
>> Soy – Healthy Alternative to Meat or Toxic Hormonal Disruptor?
>> Whey or Soy Protein for Building Muscle?
Is a High Protein Diet Safe?
There is no evidence of an upper limit where a high protein intake has adverse health effects for healthy adults.
No Tolerable Upper Intake Level for protein consumption has been established, and no adverse consequences (including cancer, kidney disease, kidney stones, and osteoporosis) of high protein intakes have been identified.11
If you already have a medical condition where high dietary protein is contraindicated, you should get professional medical advice before upping your intake. However, there is no evidence that high protein diets cause such issues.
Excess protein is used for energy and building fat-free tissue other than muscle. Eating “too much” protein might not help you increase your muscle size further, but it’s not harmful.
Here are the key takeaways from this article.
- If you are strength training regularly and eating in a caloric balance, you need about 1.6–2.2 g protein/kg/day to maximize your muscle growth and strength gains.
- A caloric deficit increases this number by about 0.5 g/kg/d. During an aggressive cut or if you’re already relatively lean, up to 3.1 g protein per kilogram of lean body mass is a good idea to protect your muscles.
- If you are 50 or older, sticking to the higher end of the 1.6–2.2 g protein/kg/day interval might be necessary to maximize your muscle growth.
The most important thing for building muscle and getting stronger is, without a doubt, your training. But hard training requires nutritional support, and eating more protein than usual is your number one tool for boosting muscle growth.
If you would like to read more about protein, be sure to check these excellent resources:
- Protein for Strength Training: The Ultimate Guide
- How Much Protein from a Single Meal Can Your Body Use to Build Muscle Mass?
- How Long Do You Build Muscle After Eating a Protein-Rich Meal?
- Eating for Muscle Growth: When, What, and How Much
- Is It Important to Eat or Drink Protein Quickly after Training?
- Protein Calculator: How Much Protein Do You Need?
- Top 15 Muscle-Building Snacks for Bodybuilding
Want to learn more about dietary supplements? Which ones are worth your money, and which are questionable or useless? Check our StrengthLog’s Supplement Guide, our free guide where we review 26 of the most popular supplements.
- ACSM Information on Protein Intake for Optimal Muscle Maintenance.
- Br J Sports Med. 2018 Mar;52(6):376-384. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults.
- J Nutr. 2017 May;147(5):850-857. Indicator Amino Acid-Derived Estimate of Dietary Protein Requirement for Male Bodybuilders on a Nontraining Day Is Several-Fold Greater than the Current Recommended Dietary Allowance.
- Nutrients. 2015 Aug; 7(8): 6874–6899. Protein Requirements and Recommendations for Older People: A Review.
- Am J Clin Nutr. 2019 Oct; 110(4): 873–882. True ileal digestibility of legumes determined by dual-isotope tracer method in Indian adults.
- ]Am J Clin Nutr. 2018 Nov; 108(5): 980–987. Ileal digestibility of intrinsically labeled hen’s egg and meat protein determined with the dual stable isotope tracer method in Indian adults.
- Sports Medicine volume 51, pages 1317–1330 (2021). High-Protein Plant-Based Diet Versus a Protein-Matched Omnivorous Diet to Support Resistance Training Adaptations: A Comparison Between Habitual Vegans and Omnivores.
- Nutrition, Volume 27, Issue 6, June 2011, Pages 727-730. Protein dietary reference intakes may be inadequate for vegetarians if low amounts of animal protein are consumed.
- Nutrients 2019, 11(12), 3016. A Comparison of Dietary Protein Digestibility, Based on DIAAS Scoring, in Vegetarian and Non-Vegetarian Athletes.
- Int J Sport Nutr Exerc Metab. 2014 Apr;24(2):127-38. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes.
- Gropper SS, Smith JL, Carr TP. Advanced Nutrition and Human Metabolism. Eighth ed. Boston MA: Cengage Learning; 2022.