Macro-nutrients like protein are big news and big business these days, and not just for gym-bros and elite athletes.
There is emerging evidence higher intakes for people over 70 (up to 0.94–1.3g per kg of bodyweight per day) might reduce age-related decline in muscle mass (known as sarcopenia). But this must be accompanied with increased resistance-based exercise, such as using weights or stretchy bands. As yet these have not been included in any national nutrient guidelines.