How Much Protein Do You Actually Need?

Protein is the one part of nutrition where the popular advice and the evidence have converged rather than diverged — which is unusual, and worth explaining properly.

The official number is a floor, not a target

The UK reference nutrient intake for protein is 0.75g per kilogram of body weight per day — about 56g for a 75kg adult.

That figure is frequently misunderstood. It was derived as the amount required to prevent deficiency in most healthy adults, not the amount associated with the best outcomes. It is a minimum to avoid a problem, not an optimum.

For most healthy adults, somewhere between 1.0 and 1.2g per kilogram is a more sensible working target — roughly 75 to 90g a day for a 75kg person.

The requirement rises with age, and this matters

From around 60 onwards, the body becomes less efficient at using dietary protein to build and maintain muscle — a phenomenon called anabolic resistance. The same meal produces less muscle protein synthesis than it would have at 30.

That means older adults need more protein, not less, which is the opposite of what most people assume and the opposite of what appetite tends to do.

European and international consensus recommendations suggest 1.0 to 1.2g per kilogram daily for healthy older adults, and 1.2 to 1.5g where there is illness or injury.

The reason this matters is sarcopenia — age-related loss of muscle mass and strength. It is a major driver of falls, fractures, loss of independence and poor outcomes after illness. Protein alone does not prevent it; protein plus resistance exercise does.

Why this matters enormously on weight-loss injections

This is the situation where protein moves from useful to important.

Medications such as tirzepatide and semaglutide work by suppressing appetite. That is the point of them — but it means total food intake falls sharply, and what tends to get dropped first is protein, because it is the most filling macronutrient and the least appealing when you are not hungry.

A meaningful proportion of weight lost on these medicines is lean tissue rather than fat. Losing muscle alongside fat means a lower metabolic rate, more weakness, and a worse position when the medication eventually stops.

Protein at every meal and resistance training twice a week are the countermeasures, and they matter more here than any amount of cardio. Roughly 1.2 to 1.6g per kilogram daily is a reasonable target while actively losing weight — which takes genuine planning on a suppressed appetite.

Where to get it

Whole foods first, and they are cheaper than supplements:

• Eggs — about 6g each
• Greek yoghurt — around 10g per 100g, roughly double standard yoghurt
• Chicken breast — about 30g per 100g
• Tinned fish — tuna, mackerel, sardines. Cheap, and the oily ones add omega-3
• Lentils, beans and chickpeas — around 8g per 100g cooked, plus fibre
• Cottage cheese — around 12g per 100g
• Tofu and tempeh — useful for plant-based diets

What about protein powder?

Whey protein is not necessary, but it is not a scam either. It is a convenient, well-absorbed and reasonably cheap way to add 20 to 25g when hitting a target from food alone is difficult — which is precisely the situation on appetite-suppressing medication or with a small appetite in later life.

Own-brand powders are chemically no different from expensive ones. The premium is marketing.

What is not worth buying: BCAA supplements, which add little over adequate total protein, and “anabolic” formulations sold at several times the price.

Distribution matters more than people expect

Spreading protein across the day works better than concentrating it in the evening meal, which is the typical British pattern — minimal at breakfast, modest at lunch, most at dinner.

Roughly 25 to 30g per meal appears to be the amount that maximally stimulates muscle protein synthesis in most adults, with more needed per meal in older people. Beyond that, additional protein in a single sitting is used for other purposes rather than wasted — but the muscle-building signal plateaus.

The practical implication: a protein-containing breakfast is the single easiest change most people can make.

Can you have too much?

In people with normal kidneys, high protein intakes have not been shown to cause kidney damage. This concern is repeated frequently and the evidence does not support it in healthy people.

The exception is genuine: if you have chronic kidney disease, protein intake should be discussed with your kidney team, and higher intakes may not be appropriate.

Very high intakes displace other useful foods — fibre in particular — which is a more realistic downside than kidney harm.

The honest summary

• Most adults: aim for 1.0 to 1.2g per kilogram daily
• Over 60: the same or a little more, and pair it with resistance exercise
• Losing weight, especially on medication: 1.2 to 1.6g per kilogram, deliberately
• Spread it across meals rather than loading the evening
• Food first; powder is a convenience, not a requirement

Protein is not a magic macronutrient, and no amount of it substitutes for overall diet quality, activity or sleep. But it is one of the few areas where the popular emphasis is broadly justified — particularly for older adults and anyone losing weight.

If you are taking a weight-loss medication and are not sure whether you are eating enough, that is a reasonable thing to raise at a review. It is a question we would rather answer early than address after a year of unintended muscle loss.