How many grams of protein per day should a 70-year-old man consume to build muscle?

1. What advocates for high targets are saying — “Push protein to drive muscle gain”

Several analyses recommend substantially higher intakes (≥1.2–2.0 g/kg/day) for older adults seeking muscle gains, and translate those/kg figures into concrete gram targets for a 70‑kg (≈154 lb) man: roughly 84–140 g/day at 1.2–2.0 g/kg, with at least one source endorsing very high targets (≈2.2 g/kg) leading to ~170 g/day for a 77‑kg man ^{[4] [2]}. These higher estimates derive from syntheses of intervention trials, mechanistic work on anabolic resistance, and the idea that older muscle requires larger protein or essential amino acid doses to maximally stimulate muscle protein synthesis. The proponents emphasize resistance exercise plus protein timing and quality to translate intake into hypertrophy, and some studies explicitly recommend per‑meal boluses of 25–35 g of high‑quality protein to reach the necessary essential amino acid threshold ^{[4] [6]}. These sources frequently aim to optimize muscle gain rather than merely prevent loss.

2. The moderate consensus — “Aim between 1.0 and 1.3 g/kg for function and preservation”

A cluster of reviews and guidance documents propose 1.0–1.3 g/kg/day as a pragmatic, evidence‑based target for older adults to preserve muscle and support physical function, translating into roughly 70–96 g/day for a ~70–80 kg man. These papers stress that this range exceeds the standard adult RDA (0.8 g/kg) and becomes most effective when paired with regular resistance exercise; they present a compromise between feasibility and anabolic benefit and are grounded in randomized and observational data showing improved lean mass, strength, and function at these intakes ^{[7] [3] [8]}. The narrative here is that modestly higher habitual intakes distributed across meals can reduce sarcopenia risk without the logistical and dietary burdens of extreme protein loads.

3. The lower bound and population associations — “Even small increases matter”

Population‑level analyses and some cohort data point to much smaller absolute changes being associated with muscle mass differences. One synthesis reports that habitual intake above 0.54 g/kg/day is positively associated with muscle changes, which for a 70–80 kg man corresponds to ~37–43 g/day ^[1]. This view emphasizes that compared to the RDA, even modest increases in older adults’ protein consumption can correlate with meaningful outcomes, and it highlights real‑world feasibility for individuals who struggle to achieve higher totals. The perspective risks understating the additional protein older muscles often require for maximal synthesis, but it correctly flags population heterogeneity and the role of total energy and exercise in mediating relationships.

4. Meal‑level evidence and the “per meal” strategy for older muscle

A recurrent mechanistic finding is that muscle protein synthesis in older adults appears to be maximally stimulated by per‑meal doses of ~25–35 g of high‑quality protein, translating into a daily strategy of 3 meals delivering those boluses (≈75–105 g/day) for maintenance or modest growth ^{[4] [6]}. This approach reframes the question from a sole daily total to protein distribution and amino acid quality, arguing that older adults benefit from even distribution and leucine‑rich sources to overcome anabolic resistance. The meal‑focused models provide a middle path between low‑intake population associations and high‑end kinetic prescriptions, and they are actionable: count grams per meal and prioritize complete proteins.

5. Reconciling differences — who needs what and why the range is wide

Divergent targets reflect different outcomes (maintenance vs maximal hypertrophy), body weight assumptions, experimental methods (epidemiology vs indicator amino acid oxidation vs anabolic response trials), and risk/benefit calculations. Studies using indicator amino acid oxidation propose higher EAR and RNI estimates (1.21–1.54 g/kg) and thus higher daily g targets, while cohort analyses emphasize minimal effective thresholds (≈0.54 g/kg) associated with better mass ^{[5] [1]}. The choice of a practical target should weigh current body mass, renal function, caloric needs, exercise regimen, and meal patterns; for a typical 70–80 kg 70‑year‑old aiming to build muscle, a defensible range is ~1.0–1.6 g/kg/day (≈70–128 g/day) with attention to per‑meal 25–35 g pulses ^{[3] [4]}.

6. Missing pieces, safety flags, and what clinicians should watch for

Key omissions in the summaries include long‑term randomized trials directly comparing high versus moderate protein intakes for hypertrophy in elderly men, individual renal or metabolic contraindications, and dietary feasibility considerations. Some high estimates (≥2.0 g/kg) may be appropriate short‑term for trained individuals but raise practicality and monitoring issues; clinicians should assess kidney function, caloric balance, and potential nutrient displacement. Finally, multiple sources emphasize pairing protein with resistance exercise and focusing on protein quality and distribution—not just total grams—to achieve the intended anabolic effect ^{[8] [4]}.