The official minimum in most countries is 0.8 g per kg of body weight daily. That figure prevents deficiency. It was never intended to describe an optimal intake, and for anyone training or over forty it is too low.
The ranges with better evidence behind them:
1.2 to 1.6 g per kg for general health, and particularly for preserving muscle from midlife onwards.
1.6 to 2.2 g per kg if you train regularly or are losing weight, where protein protects muscle while fat comes off.
For a person of 70 kg, that is roughly 85 to 155 g daily depending on which situation applies.
Muscle protein synthesis responds to a threshold at each meal rather than to a daily sum. Below roughly 25 to 30 g, the response is muted; above it, you get the full effect.
So 30 g at three meals beats 20 g at breakfast and lunch followed by 70 g at dinner, even though the totals are similar.
Most people in Britain get almost no protein at breakfast, a moderate amount at lunch, and the bulk at dinner. Fixing breakfast alone often moves someone from inadequate to sufficient.
Protein shakes are convenient rather than superior. Whole food fills you up more and brings other nutrients with it.
Older muscle responds less strongly to the same amount of protein, an effect called anabolic resistance. The same 20 g that triggered a full response at twenty-five produces a weaker one at fifty-five.
The practical answer is more protein per meal, not more meals, alongside resistance training. Training restores much of the sensitivity that age reduces.
This matters particularly for women through menopause, where falling oestrogen accelerates muscle loss at the same time appetite often shrinks.
Kidneys. In people with healthy kidneys, higher protein intakes have not been shown to cause damage across long-term studies. If you have existing kidney disease, protein does need managing with a doctor.
Bones. The old idea that protein leaches calcium has been overturned; higher intakes are associated with better bone density, particularly alongside adequate calcium.
Too much. There is a ceiling to how much protein contributes to muscle, but exceeding it is not harmful, merely unnecessary and expensive.
Related reading: Losing weight in menopause · Strength training in midlife · TDEE calculator · The food guide
Educational only, not medical advice. Speak to a doctor before raising protein intake if you have kidney disease.