Protein is having a moment. Walk down any UK supermarket aisle and you'll see protein yoghurts, protein bars, even protein crisps. But how much do you actually need — and is the official UK guideline really enough?
This guide gives you the science, the British Heart Foundation and NHS recommendations, and a calculator to work out your personal target.
The official UK number
The UK Reference Nutrient Intake (RNI) for protein is 0.75g per kg of body weight per day for healthy adults. That works out at:
- About 45g/day for an average woman (60kg)
- About 56g/day for an average man (75kg)
This is the bare minimum to prevent deficiency — not necessarily the optimum for an active person trying to lose fat or build muscle.
How much do you really need?
The honest answer depends on your goal. The 0.75g/kg figure was set in 1991, and decades of research since have shown that active adults, dieters and older people often benefit from significantly more.
| Goal | Protein per kg of body weight |
|---|---|
| General health (UK RNI) | 0.75g |
| Active adult / general fitness | 1.2–1.6g |
| Fat loss (preserve muscle) | 1.6–2.2g |
| Muscle gain (resistance training) | 1.6–2.2g |
| Older adults (60+) | 1.0–1.2g |
Worked example
If you weigh 70kg (~11 stone) and you're trying to lose fat while keeping muscle:
- Lower target: 70 × 1.6 = 112g protein/day
- Upper target: 70 × 2.2 = 154g protein/day
Why protein matters for weight loss
Three reasons protein gets singled out by dietitians for fat loss:
- It keeps you full. Protein is the most satiating macronutrient — gram for gram, it kills hunger far better than carbs or fat.
- It protects muscle. When you're in a calorie deficit, your body can break down muscle for fuel. Adequate protein plus resistance training prevents this.
- It costs more to digest. About 25% of the calories in protein are burned just digesting it — versus around 5% for carbs and 2% for fat. This is called the thermic effect of food.
What does that look like on a plate?
Hitting 100g+ of protein per day sounds like a lot until you see what it means in real food:
| Food | Portion | Protein |
|---|---|---|
| Chicken breast | 150g cooked | ~45g |
| Greek yoghurt (0%) | 200g pot | ~20g |
| Eggs | 2 large | ~13g |
| Tin of tuna | 1 (in water) | ~25g |
| Cottage cheese | 100g | ~12g |
| Lentils (cooked) | 1 cup | ~18g |
| Tofu (firm) | 100g | ~14g |
| Whey protein shake | 1 scoop | ~25g |
A simple breakfast of 2 eggs + Greek yoghurt = 33g of protein before 9am. Add a chicken salad at lunch and a piece of fish at dinner, and 120g is very achievable.
Plant-based protein
You can absolutely hit your protein target on a vegetarian or vegan diet — it just takes a bit more planning. The British Nutrition Foundation lists soy, quinoa and Quorn as plant sources that contain all essential amino acids. Beans, lentils, chickpeas, tofu and tempeh are excellent staples.
One thing to know: most plant proteins are slightly lower per portion than animal proteins, so vegan dieters often aim for the higher end of the protein target range.
Can you eat too much?
For healthy adults, the answer is essentially no. The British Heart Foundation notes there's no official UK upper limit, though regularly eating more than 2g per kg per day may strain the kidneys in people with existing kidney issues.
Do I need protein powder?
No — but it's a convenient way to top up. A whey or plant-based shake adds 20–25g of protein for around £0.50 a serving, which is cheaper than most "high protein" yoghurts and bars. The BHF makes the point that a wholegrain sandwich with two eggs delivers the same protein as a shake plus extra nutrients, so use powder as a top-up, not a replacement.
The bottom line
The UK official minimum is 0.75g per kg of body weight, but most active adults, dieters and over-60s benefit from 1.2–2.2g per kg. Use the calculator below to get your exact number, and aim to spread protein across 3–4 meals rather than loading it all into one.
Sources: British Heart Foundation (Tracy Parker, Senior Dietitian), British Nutrition Foundation, NHS Eatwell Guide, UK Reference Nutrient Intakes (1991, with updates). Always consult your GP before significantly changing your diet, especially if you have kidney or liver conditions.