Why current protein guidelines may be too low, according to a major 2026 review

The Recommended Dietary Allowance (RDA) for protein — 0.8 g per kg of body weight per day in the US — was designed decades ago to prevent deficiency in a sedentary population, not to optimise muscle maintenance, performance or healthy aging. A major 2026 review adds substantial weight to the now-large body of exercise and nutrition science arguing that figure is simply too low for most people’s actual goals.

What the review actually concludes

The review synthesises evidence pointing toward intakes well above the RDA — in the range exercise scientists have argued for over the past decade, roughly 1.6 to 2.2 g/kg for active adults — as more consistent with maintaining lean mass, supporting resistance training adaptations, and, notably, protecting muscle during aging and weight loss, two periods where protein needs rise rather than fall.

Why the RDA undersells the case for older adults specifically

Anabolic resistance — the phenomenon where aging muscle needs a larger protein stimulus to trigger the same amount of muscle protein synthesis as younger muscle — means the RDA gap is arguably widest exactly where the consequences of under-eating protein (sarcopenia, frailty, slower recovery) are most serious. The review’s emphasis on higher targets for older adults reflects this: the population the current guideline was least designed around is the population it may be shortchanging the most.

The RDA was built to prevent deficiency in a population that was not asked to build or maintain muscle. The evidence for what actually supports muscle maintenance and healthy aging points meaningfully higher.

What to do with your own number

Protein needs are individual — they scale with body weight, training volume, age and whether you are in a calorie deficit — which is exactly why a single RDA figure was always a blunt instrument. A personalised target based on your actual weight, activity level and goal is more useful than either the RDA or a single generic "eat more protein" recommendation.

Misi’s protein intake calculator computes exactly this kind of individualised target, and adjusts upward automatically for logged resistance training volume, a calorie deficit, or GLP-1 medication use — the specific scenarios this review and others flag as needing more than the RDA, not less.