Not medical advice. I am a software engineer, not a physician. This page documents my own protocol and the research I read while building it. Talk to a qualified clinician before changing your supplementation, diet or any treatment. Lab reference ranges quoted here vary by laboratory and by individual.
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The Recommended Dietary Allowance (RDA) for protein is 0.8 g/kg/day. This number is critically misunderstood. The RDA represents the minimum intake to prevent deficiency in 97.5% of the sedentary population — not the amount needed for optimal health, muscle maintenance, or athletic performance. It was established through nitrogen balance studies that measured the minimum protein needed to prevent net protein loss, not to maximize protein synthesis.
For perspective: a 70 kg person following the RDA would consume only 56 g of protein per day — roughly equivalent to two chicken breasts. For a physically active individual, this is grossly insufficient.
The gap is enormous: The RDA is 0.8 g/kg. The optimal intake for active individuals is 1.6-2.2 g/kg — that is 2-3 times higher than the RDA. Most people eating the RDA are leaving significant muscle growth, recovery, and body composition improvements on the table.
The most comprehensive analysis of protein requirements for muscle growth was published by Morton et al. in the British Journal of Sports Medicine (2018). This was a systematic review, meta-analysis, and meta-regression that analyzed:
Key findings:
Morton, R. W., et al. (2018). 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. British Journal of Sports Medicine, 52(6), 376-384. PubMed
Not all protein sources are equal. Proteins differ in their amino acid profiles, which directly affects their ability to stimulate muscle protein synthesis (MPS).
Complete proteins contain all 9 essential amino acids (EAAs) in adequate proportions. Sources include: meat, poultry, fish, eggs, dairy, soy, and quinoa. Incomplete proteins are low in one or more EAAs. Most plant proteins (beans, grains, nuts) are incomplete individually but can be combined to provide all EAAs (e.g., rice + beans).
The protein quality can be measured using the Digestible Indispensable Amino Acid Score (DIAAS). A study by Rutherfurd et al. (2015) measured DIAAS values for common foods and found: whole milk powder (1.18), eggs (1.13), chicken breast (1.08), soy protein isolate (0.90), pea protein (0.82), rice protein (0.37). Values above 1.0 indicate excellent quality; below 0.75 indicates a limiting amino acid.
Leucine is the most potent amino acid for triggering muscle protein synthesis through the mTOR signaling pathway. Research by Churchward-Venne et al. (2012) and others has established that a threshold of approximately 2.5-3 g of leucine per meal is needed to maximally stimulate MPS.
To reach the leucine threshold, you typically need:
Churchward-Venne, T. A., et al. (2012). Role of protein and amino acids in promoting lean mass accretion. J Food Sci, 77(8), H114-20. PubMed
How you distribute protein throughout the day matters. Mamerow et al. (2014) compared two groups eating the same total daily protein (90 g) distributed either evenly (30 g per meal x 3) or skewed (10 g breakfast, 15 g lunch, 65 g dinner). The even distribution group achieved 25% greater MPS over 24 hours.
The optimal approach is to distribute protein across 4-5 meals, each containing 0.4-0.55 g/kg of body weight. For a 75 kg person targeting 2.0 g/kg/day (150 g total), this means 30-37 g per meal across 4-5 meals.
Mamerow, M. M., et al. (2014). Dietary protein distribution positively influences 24-h muscle protein synthesis. J Nutr, 144(6), 876-880. PubMed
Pre-sleep protein: Trommelen et al. (2017) demonstrated that consuming 40 g of casein protein before sleep increased overnight MPS by 22% compared to placebo, without affecting fat oxidation or next-morning appetite. This is an easy strategy to increase daily protein intake.
When in a caloric deficit, protein needs increase substantially. The body is in a catabolic state, and higher protein intake is needed to preserve lean mass. Helms et al. (2014) conducted a systematic review of protein needs during caloric restriction in resistance-trained lean athletes and recommended 2.3-3.1 g/kg of fat-free mass per day (approximately 2.2-2.7 g/kg of total body weight for lean individuals).
A landmark study by Longland et al. (2016) compared two groups of 40 overweight young men on the same 40% caloric deficit for 4 weeks, with one group consuming 1.2 g/kg and the other consuming 2.4 g/kg of protein. Both groups did resistance training and HIIT. Results:
Longland, T. M., et al. (2016). Higher compared with lower dietary protein during an energy déficit combined with intense exercise promotes greater lean mass gain and fat mass loss. Am J Clin Nutr, 103(3), 738-746. PubMed
Helms, E. R., et al. (2014). A systematic review of dietary protein during caloric restriction in resistance trained lean athletes. Int J Sport Nutr Exerc Metab, 24(2), 127-138. PubMed
| Food | Protein per 100g | Leucine per 100g | DIAAS |
|---|---|---|---|
| Chicken breast | 31 g | 2.4 g | 1.08 |
| Eggs (whole) | 13 g | 1.1 g | 1.13 |
| Greek yogurt | 10 g | 0.9 g | 1.09 |
| Whey protein | 80 g | 10 g | 1.09 |
| Salmon | 25 g | 1.8 g | 1.04 |
| Lean beef | 26 g | 2.0 g | 1.10 |
| Tofu (firm) | 17 g | 1.2 g | 0.90 |
| Lentils (cooked) | 9 g | 0.6 g | 0.72 |
A 2025 updated review comparing NMN and NR in Food Frontiers confirmed that the leucine threshold of 2.5-3.0 g per meal remains the key trigger for maximizing mTOR-mediated muscle protein synthesis. New research has clarified the practical difference between plant and animal protein sources: animal proteins contain an average of 8.8% leucine versus 7.1% for plant proteins, meaning plant-based eaters need approximately 20-30% more total protein per meal to reach the same leucine threshold. A 2024 study in Nutrients demonstrated that plant-based diets for male rugby players can achieve 2.9 g leucine per meal across four daily meals, exceeding the anabolic threshold, but this requires careful food selection emphasizing soy, pea protein isolate, and lentils.
A 2026 analysis raised a new concern: chronically elevated mTOR activation from very high leucine intake may carry cardiovascular risks. While the clinical significance remains under investigation, this supports the existing recommendation of distributing protein across 3-4 meals rather than consuming extremely large single-meal boluses. The practical sweet spot remains 25-40 g of high-quality protein per meal for most active adults.
Nutrients (2024). Protein and Leucine Requirements for Maximal Muscular Development Are Achieved with Plant-Based Diets in Adult Male Rugby Players. PubMed Central