Protein
Protein is a macronutrient made of chains of amino acids, found in foods such as meat, fish, eggs, dairy, legumes and grains.
What it is studied for
The strongest rated effects first. Bars show the size of the effect, the letter grades the evidence, and each rating lists the studies behind it.
What does protein do?
Protein supplies amino acids used to build, maintain and repair muscle. Resistance exercise and adequate protein work together in the muscle’s adaptation to training. 1
What counts as enough?
German DGE reference values for healthy adults are 0.8 g/kg body weight daily at ages 19–64 and an estimated 1.0 g/kg from age 65. These describe total dietary intake, not a supplement dose; for overweight adults, reference calculations use normal weight. 2
Key studies
The most recent publications linked to Protein's ratings.
Why people take it
SuppCo community snapshot, 2026-09-28. Reasons for use are not evidence that it works.
Questions people ask
Do recreational exercisers need more?
DGE does not assign a higher requirement to recreational exercise of about 30 minutes four or five times weekly. 3
What intake is discussed for athletes?
Sports guidance summarized by NIH describes 1.2–2.0 g/kg/day total protein, tailored to training. 1
Is the reference value the same after age 65?
No. DGE gives an estimated 1.0 g/kg/day for healthy adults aged 65 and older. 2
Do requirements change during pregnancy?
DGE values rise to 0.9 g/kg/day in the second trimester and 1.0 in the third; breastfeeding has a 1.2 g/kg/day reference. These are total-intake values. 2
Related nutrients
Soy ProteinSources
- Dietary Supplements for Exercise and Athletic Performance NIH Office of Dietary Supplements
