How much protein per meal?
Muscle protein synthesis (MPS) is the process of building new skeletal muscle tissue. When MPS chronically exceeds
muscle protein breakdown (MPB), resulting in a positive net protein balance, we can expect muscle growth over the long term.
[117][118] Each time you eat represents an opportunity to promote muscle growth through the stimulation of MPS.
Protein-feeding studies using various doses of
whey protein suggest that 0.24 g/kg/meal will maximize the MPS of the
average young adult,
[51] whereas 0.40 g/kg/meal will maximize the MPS of
most young adults.
[119] For older adults, these two values jump to 0.40 and 0.60 g/kg/meal.
[51]
Desirable minimal protein intake range per meal and age
| Body weight (lb) | Body weight (kg) | 20s | 30s, 40s, 50s | ≥60 |
|---|
| 100 | 45 | 11–18 | 13–24 | 18–27 |
| 125 | 57 | 14–23 | 16–30 | 23–34 |
| 150 | 68 | 16–27 | 20–36 | 27–41 |
| 175 | 79 | 19–32 | 23–42 | 32–48 |
| 200 | 91 | 22–36 | 26–48 | 36–54 |
| 225 | 102 | 24–41 | 30–54 | 41–61 |
| 250 | 113 | 27–45 | 33–60 | 45–68 |
| 275 | 125 | 30–50 | 36–66 | 50–75 |
| 300 | 136 | 33–54 | 39–72 | 54–82 |
The ranges in this table represent individual variations. The minimum protein requirements increase as you age, but to what degree is uncertain because of the age gap left by the studies: most subjects were in their 20s (0.24–0.40 g/kg) or 60s/70s (0.40–0.60 g/kg). For people in their 30s, 40s, or 50s, the 0.29–0.53 g/kg range reflected in this table is an educated guess.
References: Schoenfeld and Aragon.
J Int Soc Sports Nutr. 2018.
[120] Rafii et al.
J Nutr. 2016.
[7] Morton et al.
Front Physiol. 2015.
[119] Moore et al.
J Gerontol A Biol Sci Med Sci. 2015.
[51] Rafii et al.
J Nutr. 2015.
[8]
Your mileage may vary. The ranges above are not
ideal ranges. Instead, they cover the known extent of interindividual variations among healthy adults. In other words, if you’re in your 20s, you don’t need to calculate your protein intake per meal so that it falls precisely within the 0.40–0.60 g/kg range. Rather, your
minimum protein intake per meal (to maximize MPS) is likely to fall within that range.
Further, there are at least
three good arguments in favor of eating toward or even above the higher end of your range:
First, the ranges we listed are derived from studies using
whey protein in isolation. Whey protein is highly bioavailable, rich in
essential amino acids (EAAs), and quickly digested. When eating lower-quality or slower-digesting proteins (as would occur when eating a meal,
especially one rich in plant-based foods), higher protein intakes are probably required.
Second, while these values suggest a protein-intake threshold for maximally stimulating MPS, there is no known threshold for
whole-body protein balance.
[121] For example, a study using meals with lean beef found that 40 and 70 grams of protein (0.5 and 0.8 g/kg) led to similar increases in MPS, but that 70 grams led to greater increases in whole-body protein synthesis and greater decreases in whole-body protein breakdown.
[122] In other words, eating more protein may not necessarily translate to greater
muscle-protein turnover and growth, but since muscle tissue accounts for only 25–30% of whole-body protein turnover,
[123] the additional protein is not “wasted” (a common myth).
Third, as shown above in the
Prevalence of sarcopenia by age and sex in the US graphic, even people in their twenties can suffer from sarcopenia — in which case they would benefit from a protein intake closer to the one recommended in this table for adults over sixty.
You may have heard that if you eat more than 30 grams of protein in one sitting, the “excess” will pass undigested, but that’s just a myth. It is however true that spreading your protein intake over a few meals, making sure that you meet your
desirable minimal protein intake per meal with each meal, will generally result in greater lean mass and strength. A pragmatic review article suggests that, to maximize their lean mass, active adults should consume 1.6–2.2 g/kg/day spread across four meals (0.40–0.55 g/kg/meal).
[120]
For maximal stimulation of muscle protein synthesis, aim for a per-meal dose of quality protein (such as can be found in meat, eggs, and dairy) of 0.4–0.6 g/kg. Higher doses will not be wasted and are probably necessary when eating mixed meals that contain a variety of protein sources.
