Protein: the most important macro for body composition
The RDA (0.8 g/kg) prevents deficiency but is far below the optimum for active adults. Modern sports science recommends 1.6–2.2 g/kg for muscle gain and 1.8–2.7 g/kg in a calorie deficit.
Spread intake across 3–5 meals of 25–40 g protein to keep muscle protein synthesis elevated throughout the day.
Quality matters: complete proteins (animal, soy, whey) score higher on the DIAAS scale than most plant sources alone.