How Much Protein Do You Really Need? (2025)

Start with grams per kilogram

The single most useful thing you can learn about protein is to think in grams per kilogram of body weight, not vague 'eat more protein' advice. The baseline Recommended Dietary Allowance is 0.8 g/kg/day — enough to prevent deficiency in a sedentary adult. But 'not deficient' isn't the same as 'optimal.'

If you train, aim higher

For people who lift or train regularly, most sports-nutrition bodies converge on roughly 1.2–2.0 g/kg/day to support muscle repair and growth. The Harvard T.H. Chan — Protein emphasizes that source quality matters as much as quantity — favor fish, poultry, legumes, and nuts over processed and red meats.

A worked example

A 70 kg recreational lifter targeting 1.6 g/kg needs about 112 g of protein a day. Split across four meals, that's ~28 g each — a chicken breast, a cup of Greek yogurt with nuts, a lentil bowl, and a couple of eggs get you there without exotic powders.

Older adults need more, not less

After about age 60, muscle becomes harder to maintain (sarcopenia). Higher protein — toward the upper end of that range, spread through the day — combined with resistance exercise helps preserve strength and independence.

Getting enough on plants

Plant eaters can absolutely meet needs by combining legumes, soy, grains, nuts, and seeds across the day. You don't need to 'combine proteins' at every meal — variety over the day covers all essential amino acids. Total intake and consistency matter more than perfect timing.

How much protein you actually need

For most adults, the baseline is about 0.8 grams per kilogram of body weight per day, but active people, older adults, and those losing weight benefit from more — roughly 1.2 to 2.0 g/kg depending on goals. The Harvard T.H. Chan — Protein reviews the evidence and cautions that quality and source matter as much as quantity. Spreading intake across meals (roughly 20–40 g each) supports muscle maintenance better than one large serving.

Best protein sources and quality

Animal proteins — eggs, dairy, fish, poultry, lean meat — are 'complete', containing all essential amino acids. Plant proteins like beans, lentils, tofu, and whole grains are excellent too; eating a variety across the day covers the amino-acid bases. Favor sources that come with other benefits: fish adds omega-3s, legumes add fiber. The NHLBI — Heart-Healthy Foods recommends lean and plant proteins for heart health.