How Much Protein Do You Really Need?

Protein is the nutrient most talked about in the gym – and the one surrounded by the biggest misunderstandings. Some drink three shakes a day "to be safe", others fear for their kidneys. The truth lies in between and is pleasingly well researched.

You can work out your personal number – including a check against what you eat – in a minute with the free protein calculator.

This article belongs to the Nutrition & Body Composition topic. How protein fits into a diet is explained in Lose fat, keep muscle.

Why protein matters so much

Protein provides amino acids, the building blocks for muscles, enzymes, hormones and the immune system. For people who train, three effects are crucial:

• Building and maintaining muscle: training provides the stimulus, protein provides the material.
• Satiety: protein fills you up more than carbohydrates and fat – a big advantage in a diet.
• Thermic effect: a larger share of the calories from protein is used up by digestion itself.

Needs at a glance

• No training (0.8 g/kg)64 g
• Aged 65+ (approx. 1.0 g/kg)80 g
• Endurance training (1.2–1.6 g/kg)96–128 g
• Muscle building (1.6–2.2 g/kg)128–176 g
• Strength training while dieting (1.8–2.4 g/kg)144–192 g

›以表格顯示資料

類別	g protein per day
No training (0.8 g/kg)	64 g
Aged 65+ (approx. 1.0 g/kg)	80 g
Endurance training (1.2–1.6 g/kg)	96–128 g
Muscle building (1.6–2.2 g/kg)	128–176 g
Strength training while dieting (1.8–2.4 g/kg)	144–192 g

The figure of 1.6 g comes from a large meta-analysis that pooled studies on strength training and protein intake. Above this amount, gains in lean mass barely rose on average; the upper limit of the statistical range was about 2.2 g. That is where the common recommendation of 1.6–2.2 g per kilogram comes from.

Worked example

A person weighing 80 kg who wants to build muscle:

• Lower limit: 80 × 1.6 = 128 g of protein per day
• Upper limit: 80 × 2.2 = 176 g of protein per day

With significant excess weight, it's better to calculate with your target weight or lean mass; otherwise the numbers become unrealistically high.

Protein in a diet: why more makes sense

In a calorie deficit, the body also draws energy from muscle protein. A higher protein intake together with strength training protects muscle. At the same time, protein keeps you full longer, which makes the deficit easier to bear. For lean, trained people in a longer diet, up to 2.4 g per kilogram is sometimes recommended.

Protein after 50: needs increase

With age, muscles respond less strongly to protein – known as "anabolic resistance". That doesn't mean building muscle becomes impossible, but that it needs more protein per meal and regular strength training. For older people who train, 1.2–1.6 g per kilogram and meals with more like 30–40 g of protein make sense. More in Muscle building after 40.

Spreading it across the day

The total amount matters most. Even distribution still makes sense:

• 3–5 meals with 20–40 g of protein each.
• About 0.4 g per kilogram of body weight per meal as a rough guide.
• A protein-rich meal in the hours around training – exact timing is less important than once thought.
• Optionally before bed: quark or skyr provide slowly digested protein for the night.

Ideas for high-protein meals are in High-protein breakfast and High-protein snacks.

The best protein sources

Figures are rounded guide values; they vary by product.

Plant protein

Vegan and vegetarian diets can easily cover protein needs. Two points help:

• Combine: legumes and grains complement each other's amino acid profiles.
• Plan a little more: some plant proteins are slightly harder to digest and contain less leucine – the amino acid that particularly triggers muscle building. About 10 percent more total protein makes up for it.

Soy, pea protein and combinations of the two are good supplements in powder form.

Do you need protein powder?

No, but it can be practical. Protein powder is a food, not a miracle product – it makes it easier to reach your daily amount if your normal diet falls short. Whether whey makes sense and what to look for when buying is explained in Whey protein: do you really need protein powder?.

Is too much protein harmful?

Kidneys: in healthy people, studies with high protein intakes have shown no decline in kidney function. With existing kidney disease, however, too much protein can be a burden – the amount should then be set by a doctor.

Bones: the former concern that protein draws calcium from the bones has not been confirmed. Adequate protein intake seems rather to support bone health.

Digestion: a lot of protein at once, especially from shakes, can cause bloating. Whole foods and fibre help.

Common mistakes

Relying only on shakes. Whole-food protein sources also provide micronutrients and fill you up better.

Breakfast without protein. Bread with jam provides hardly any protein. If you manage 30 g in the morning, the daily amount is much easier to reach.

Calculating with body weight instead of target weight when significantly overweight – that leads to unrealistic amounts.

Protein without training. Protein alone doesn't build muscle. The stimulus comes from training, for example with the 3-day full-body plan.

Conclusion: enough is enough

For most people who train, the answer is simply: about 1.6 to 2.2 g of protein per kilogram of body weight, spread over several meals. If you hit that, you have done everything right on protein – more brings hardly any extra benefit. How to combine protein with carbohydrates and fat into a coherent diet is explained in Macronutrients: the optimal split; how to prepare your meals for the week in the meal prep guide.