Why these numbers
The recommendations follow the research consensus for people who lift: 1.6–2.2 g of protein per kg of bodyweight per day maximizes muscle growth at maintenance calories or in a surplus. Meta-analyses find no additional hypertrophy above roughly 1.6 g/kg on average, with the upper end covering individual variation.
In a calorie deficit the target shifts up to 1.8–2.4 g/kg: higher protein preserves lean mass while you lose fat, and it keeps you fuller — the most practical advantage when calories are low.
Very lean or very heavy?
At high body fat, bodyweight-based targets overshoot — the extra protein is not harmful, just unnecessary. If you know your body fat percentage, anchoring to lean mass (about 2–2.4 g per kg of lean mass) is more precise. Estimate it with the body fat calculator first.
Hitting the target
Whole-food protein sources — meat, fish, eggs, dairy, legumes — should carry most of the total. A scoop of whey is a convenient 20–25 g when a meal falls short. Spreading intake across 3–5 meals of 0.4–0.5 g/kg is a small optimization; the daily total is what matters.