The baseline Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of bodyweight per day. According to Harvard Health, that figure is designed to prevent deficiency in a sedentary adult — it's not a target for anyone trying to build or maintain muscle through regular training.
The range that actually matters for lifters
Mayo Clinic Health System recommends that people who regularly lift weights or train for endurance events consume between 1.2 and 1.7 grams of protein per kilogram of bodyweight daily. Harvard Health cites similar research suggesting that even older adults trying to preserve muscle mass benefit from roughly 1 to 1.6 grams per kilogram — meaningfully above the baseline RDA, but nowhere near the extreme numbers sometimes promoted in bodybuilding culture.
Translated into practical terms: a 80 kg (176 lb) lifter training regularly would target somewhere between 96 and 136 grams of protein a day, not 250+. Our calculators page uses 2 grams per kilogram as a simple, slightly generous target that comfortably covers this range without requiring precise tracking.
Is more protein ever better?
Not really, and it isn't free. Harvard Health notes that experts advise caution around very high intakes — 2 grams per kilogram or more sustained long-term — since the evidence for extra benefit above that range is weak, while Mayo Clinic Health System points out that excess protein intake typically just gets used for energy or stored, rather than building additional muscle. Muscle growth is driven primarily by the training stimulus — see progressive overload — with protein supplying the raw material to repair and build from that stimulus, not replacing the need for it.
Where should the protein come from?
Both sources emphasize whole-food protein first: lean meats, fish, eggs, dairy, legumes, and tofu, with powders as a convenient supplement rather than a replacement. See our nutritious foods list for specific protein sources organized alongside carbohydrates and fats.
The takeaway
Aim for roughly 1.2–1.7 grams of protein per kilogram of bodyweight if you train regularly — our calculator's 2g/kg target sits at the generous end of that range on purpose, so you don't have to be exact. Beyond that point, more protein isn't doing much extra work; your training and recovery matter more.