Nutrition · Moderate evidence
Protein and Training Adaptation
Sufficient protein can support gains in lean mass and strength alongside training; the response varies and does not increase indefinitely with higher intakes.
Systematic review, meta-analysis, and meta-regression; society position stand · 2 sources · 2 min
What the studies show
- Protein supplementation increased lean mass and strength in individuals engaging in resistance training.
- The benefit plateaued at approximately 1.6 g per kg of body weight per day on average, with the upper limit of the confidence interval near 2.2 g/kg.
- The ISSN recommends 1.4 to 2.0 g/kg/day for most exercising individuals.
How Letz applies it
The Letz protein target uses 1.6 to 2.2 g/kg depending on the goal, calculated using whichever is lower between current weight and target weight.
Numbers derived from this rule
| Parameter | Range | Weight | Rule |
|---|---|---|---|
| Daily protein | 1.6–2.2 g/kg/day2 variants by context | 90% | 1.6 to 2.2 g/kg/day for those who train; in a deficit, the upper end of the range protects lean mass.Protein and Training Adaptation · Higher Protein Intake During a Calorie Deficit |
Who it applies to
Healthy adults performing resistance training.
Limits
This is not an individual prescription and requires adjustments for total energy intake, clinical status, personal preference, and tolerance.
Sources
- Morton et al., British Journal of Sports Medicine, 2018 DOI 10.1136/bjsports-2017-097608
- Jäger et al., Journal of the International Society of Sports Nutrition, 2017 DOI 10.1186/s12970-017-0177-8
More in Nutrition
- Higher Protein Intake During a Calorie DeficitIn a deficit, higher protein protects lean mass and can even allow muscle gain alongside intense training; the effective range rises to approximately 1.6 to 2.4 g/kg.
- Rate of weight lossLosing weight slowly, at around 0.5 to 1% of body weight per week, better preserves lean mass, strength, and metabolic rate compared to rapid weight loss.
- Distribute protein throughout the dayDividing protein into servings of around 0.4 g/kg across four or more meals stimulates protein synthesis more than concentrating everything into one or two.
- Protein in older adultsOlder adults need more protein per meal to stimulate muscle synthesis; consensus guidelines recommend 1.0 to 1.2 g/kg/day or more for those who train.