Protein is the most argued-about nutrient in fitness and one of the least complicated once you understand the single fact that changes everything after forty.
That fact is anabolic resistance. As you age, your muscles become less responsive to protein. The same meal that triggered a strong muscle-building response at twenty-five produces a weaker one at fifty. Nothing about your diet has changed. Your response to it has.
The practical consequence is counterintuitive. Older adults need more protein than younger adults to achieve the same result, not less, at exactly the age when most people are eating less of it.
The number, and where it comes from
The official minimum recommendation in most countries is around 0.8 grams of protein per kilogram of body weight per day. That figure was established to prevent deficiency in the general population. It is a floor, not a target, and it was never intended as an optimum for maintaining muscle.
The research on muscle protein synthesis in older adults consistently supports a considerably higher intake. The range that comes up repeatedly for adults over forty who are training is roughly 1.4 to 2.0 grams per kilogram of body weight per day, with around 1.6 g/kg being a sensible working target for most people.
For an 80 kg person, that is roughly 128 grams a day. For a 65 kg person, roughly 104 grams.
Most people over forty who are not deliberately tracking are eating well under that, often around half.
Distribution matters as much as the total
This is the part that gets missed. Hitting your daily total in one large dinner is not equivalent to spreading it across the day.
Muscle protein synthesis is triggered per meal, and it requires a threshold dose to switch on. Below that threshold, the protein is still used, but it does not produce a meaningful muscle-building signal. Above it, you get the response. Well above it, you do not get proportionally more.
For adults over forty, the threshold sits at roughly 25 to 40 grams of quality protein per meal, and it is at the higher end of that range compared with younger adults because of anabolic resistance.
Which means three meals containing 35 grams each beats one meal containing 105 grams, even though the daily total is identical.
The typical South African eating pattern works against this. Toast or cereal in the morning, a light lunch, then most of the day’s protein at dinner. That is one meaningful muscle-building signal a day when you could have three.
What 30 to 40 grams actually looks like
Useful to know by sight rather than by app:
- A palm-sized chicken breast, roughly 150 g cooked: about 45 g
- A 150 g portion of hake or salmon: about 30 g
- Two large eggs plus a cup of milk: about 20 g
- A cup of plain double-cream yoghurt: about 15 to 20 g
- A cup of cottage cheese: about 25 g
- 150 g lean beef mince: about 35 g
- A cup of cooked lentils: about 18 g
- A standard whey shake: about 25 g
Breakfast is where most people have the largest gap and the easiest fix. Adding eggs, yoghurt or a shake to a carbohydrate-led breakfast moves someone from roughly 8 grams to roughly 30 in a single change.
Protein alone does nothing
This has to be said plainly, because the supplement industry has done a good job of implying otherwise.
Protein is the building material. Resistance training is the instruction to build. Without the instruction, additional protein does not become muscle. Someone eating 150 grams a day and not training is producing expensive urine.
The combination is what works, and the training half is the non-negotiable one. That is the argument made at length in why muscle is the organ of longevity, and it is why sarcopenia is a training problem before it is a nutrition problem.
Common questions
Is high protein bad for your kidneys? In people with healthy kidney function, the research does not support this. It is a genuine concern for people with existing kidney disease, who should follow medical advice. For everyone else it is a myth that has outlived its evidence.
Do I need a shake? No. Whole food works perfectly well. A shake is a convenience tool for the meal where hitting the threshold with food is difficult, usually breakfast or straight after training.
Does timing around the workout matter? Far less than the internet suggests. The anabolic window is measured in hours rather than minutes. Daily total and per-meal distribution matter considerably more than whether you drink something within thirty minutes of finishing.
What about plant protein? It works, but plant sources generally have a lower leucine content and a less complete amino acid profile, so the threshold dose is higher. Plan for roughly 20 to 30 percent more, and vary your sources.
Start here
If you change one thing, make it breakfast. If you change two, add a protein source to lunch. That alone moves most people over forty from one muscle-building signal a day to three, without counting anything.
Then make sure the training half is in place, because that is what turns the protein into something.
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