How much protein is needed per day for muscle gain?
Pro Research Analysisby 
Searched over 200M research papers
Consensus Meter
Daily Protein Requirements for Muscle Gain
Optimal Protein Intake for Muscle Synthesis
Research indicates that the optimal protein intake for muscle protein synthesis (MPS) in young adults is around 20-25 grams of high-quality protein per meal. This amount maximizes MPS, with excess protein being oxidized for energy or converted to other compounds. However, when protein is consumed with other macronutrients, absorption is delayed, potentially enhancing amino acid utilization for muscle building. To maximize muscle anabolism, it is recommended to consume 0.4 grams of protein per kilogram of body weight per meal, spread across at least four meals, totaling a minimum of 1.6 grams per kilogram per day. The upper limit suggested is 2.2 grams per kilogram per day, distributed similarly.
Dose-Response Relationship in Protein Intake
A systematic review and meta-analysis of randomized controlled trials (RCTs) found that muscle mass significantly improves with an increase in daily protein intake. The effect is more pronounced with supplementary protein intake exceeding 50 grams per day. This suggests that higher protein intake can sustain and improve muscle mass across various populations, regardless of sex, age, or exercise habits.
Protein Intake and Resistance Exercise
Increasing daily protein intake has been shown to enhance gains in lean body mass (LBM) and muscle strength, particularly in individuals engaged in resistance exercise (RE) training. Studies indicate that consuming 1.6 grams of protein per kilogram per day is effective for younger adults, while older adults benefit from 1.2-1.59 grams per kilogram per day . Protein supplementation beyond 1.62 grams per kilogram per day does not yield additional gains in fat-free mass (FFM) during RE training.
Protein Requirements for Novice Bodybuilders
In novice bodybuilders undergoing intensive training, protein needs are approximately double the current recommendations, around 1.4-1.5 grams per kilogram per day. However, increasing protein intake from 1.35 to 2.62 grams per kilogram per day does not significantly enhance muscle mass or strength gains in the initial month of training. This suggests that while higher protein intake is necessary, there is a threshold beyond which additional protein does not further benefit muscle growth in the short term.
Recommendations for Athletes
Athletes, particularly those involved in resistance training, may require higher protein intakes than the general population. Recommendations range from 1.3 to 1.8 grams per kilogram per day, consumed in 3-4 isonitrogenous meals to maximize muscle protein synthesis. During periods of high-frequency or high-intensity training, protein intake may need to be as high as 1.8-2.0 grams per kilogram per day to prevent lean mass loss during caloric deficits.
Safety and Upper Limits of Protein Intake
For healthy adults, long-term consumption of protein up to 2 grams per kilogram per day is considered safe, with the tolerable upper limit being 3.5 grams per kilogram per day for well-adapted individuals. However, chronic high protein intake above 2 grams per kilogram per day may lead to digestive, renal, and vascular issues and should be avoided.
Conclusion
To optimize muscle gain, individuals should aim for a daily protein intake of 1.6 grams per kilogram of body weight, distributed across multiple meals. For those engaged in resistance training, slightly higher intakes may be beneficial, but exceeding 1.62 grams per kilogram per day does not provide additional benefits. It is crucial to balance protein intake with overall dietary needs and exercise regimens to achieve the best results in muscle mass and strength gains.
Sources and full results
Most relevant research papers on this topic