If you're lifting weights and want to build muscle, eating at least 1.6 grams of protein per kilogram of body weight every day is the biggest factor that helps — more protein means better results, and when you eat it doesn't matter as much.
See the scientific wording
A total daily protein intake of at least 1.6 g/kg/day is the strongest predictor of muscle hypertrophy gains in individuals performing resistance training, and each additional 0.5 g/kg/day increase in protein intake is associated with approximately a 0.2 increase in effect size, indicating that total protein consumption is more important than timing for maximizing muscle accretion.
Very strong evidence
Randomized trialsOne good-quality study supports this claim.
What the research says
1 study reviewedSupporting (1)
The effect of protein timing on muscle strength and hypertrophy: a meta-analysis
Systematic Review With Meta-AnalysisMeta-analysis2013
This study found that it doesn’t matter when you drink your protein shake — before or after the gym — what really matters is how much protein you eat all day. More total protein = bigger muscles, no matter the timing.
Contradicting (0)
No contradicting studies found yet
That doesn't mean it's settled — it just means no study has tested the opposite.
Quality-weighted scoring: we follow the GRADE framework — each study is rated High, Moderate, Low, or Very Low based on study design, methodology rigor, and risk of bias. A single high-quality RCT can outweigh several weaker observational studies.
Scores reflect study quality, not just count.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting study
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If you're lifting weights and want to build muscle, eating at least 1.6 grams of protein per kilogram of body weight every day is the biggest factor that helps — more protein means better results, and when you eat it doesn't matter as much.
Evidence from Studies
Supporting (1)
Community contributions welcome
The effect of protein timing on muscle strength and hypertrophy: a meta-analysis
This study found that it doesn’t matter when you drink your protein shake — before or after the gym — what really matters is how much protein you eat all day. More total protein = bigger muscles, no matter the timing.
Contradicting (0)
Community contributions welcome
Score Breakdown
No multi-axis breakdown available yet. The overall Pro / Against score above is the best signal.
- No clinical evidence is available; the score reflects mechanistic plausibility only.
What Would Prove This
Per GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this claim, ordered from strongest to weakest.
Systematic Review & Meta-Analysis of Protein Intake Doses (1.6–2.2 g/kg/day) and Muscle Hypertrophy in Resistance-Trained Adults
Includes only RCTs in resistance-trained humans with direct measurement of muscle hypertrophy (e.g., DEXA, MRI), comparing protein intakes ≥1.6 g/kg/day vs lower intakes, with or without timing manipulation, over ≥8 weeks.
Double-Blind RCT Comparing 1.6 vs 2.1 g/kg/day Protein Intake on Muscle Hypertrophy in Resistance-Trained Men and Women
Randomized, double-blind, parallel-group trial in resistance-trained adults; two groups: 1.6 g/kg/day vs 2.1 g/kg/day; all protein consumed in same timing pattern; 12-week intervention; primary outcome: muscle cross-sectional area via MRI.
Prospective Cohort Study of Daily Protein Intake and Muscle Gain Over 6 Months in Resistance-Trained Individuals
Longitudinal cohort of 500+ resistance-trained adults tracking daily protein intake (food logs), training volume, and muscle mass changes (DEXA) over 6–12 months; analyzes association between intake increments (0.5 g/kg/day) and effect size changes.
Case-Control Study Comparing Protein Intake Patterns in High vs Low Responders to Resistance Training
Identifies 'high responders' (≥0.2 effect size increase) and 'low responders' (<0.1 effect size) after 12 weeks of standardized resistance training; retrospectively compares their total daily protein intake and timing patterns.
Cross-Sectional Survey of Protein Intake and Muscle Mass in Resistance-Trained Adults
Survey of 1000+ resistance-trained individuals measuring self-reported protein intake and muscle mass via bioimpedance; analyzes correlation between intake levels (e.g., 1.6 vs 2.0 g/kg/day) and muscle size.