Protein: How Much You Actually Need

01The basics

Protein is the building block for pretty much everything in your body that has structure or function: muscles, skin, hair, enzymes, hormones, antibodies. Unlike fat, your body can barely store protein, so it needs a steady supply from food.

In coaching, protein is usually the first lever we adjust — not because it's the only thing that matters, but because it has the most direct effect on two things a lot of people struggle with day to day: staying full and keeping muscle mass. At the same time, protein comes with its share of stubborn myths, chief among them the fear that eating a lot of it damages your kidneys. Time to look at what the evidence actually says.

02What the science says

How much protein does a healthy adult need?

The DGE (Deutsche Gesellschaft für Ernährung, Germany's nutrition science authority) sets the reference value at 0.8 g of protein per kg of body weight per day for healthy adults aged 19–64 — the same for both sexes. For people carrying excess weight, the calculation uses normal body weight rather than actual body weight. For adults 65 and older, the DGE recommends 1.0 g/kg, because the body becomes less efficient at converting protein into muscle with age.

But that's baseline coverage for an average, lightly active person — not a target. If you train regularly, are in a calorie deficit, or want to build muscle, you'll generally do much better with 1.0–1.5 g of protein per kg of body weight. At 85 kg that's roughly 85–128 g a day; at 100 kg, roughly 100–150 g.

Why protein helps you stay full

Of all three macronutrients, protein is the most reliably filling — a finding that's consistent across reviews looking at the link between protein intake and satiety. This effect is one of the main reasons higher-protein meals make it easier, in practice, to stick to a calorie deficit without constant hunger.

The side effect: digesting protein burns calories too

Every food costs your body some energy just to digest — known as diet-induced thermogenesis. For carbohydrates that's roughly 5–10% of the calories you take in; for fat, just 0–3%. Protein sits clearly above both at 20–30%: out of 100 kcal from protein, your body burns up to 30 kcal again just processing it. This isn't a free pass to eat without limits, but it's part of why a higher-protein diet often feels easier at the same total calorie count.

Does a lot of protein harm your kidneys?

A worry we hear often in coaching. In 2023, the DGE published a review evaluating studies with protein intakes between 1.0 and 3.3 g/kg of body weight: for healthy people, it found no evidence that high protein intake raises the risk of kidney stones or kidney disease.

In practical terms: if your kidneys are healthy and you have no pre-existing condition, you don't need to be afraid of a high-protein diet. As a rough guideline, up to about 2.0 g/kg of body weight per day is considered safe for healthy people — even long-term, not just short-term. The evidence only gets thinner at extremely high amounts (well above 2.0 g/kg) sustained over many years, simply because real long-term studies on that are still missing. It's a different story if you already have kidney disease — there, individual, usually lower limits should be set by your doctor.

Protein and aging: more matters, not less

As we age, the body naturally loses muscle mass (sarcopenia), partly because muscles become less responsive to the growth signal that protein provides. Literature on nutrition in older adults therefore recommends getting at least around 25–40 g of protein per main meal, rather than concentrating the day's total into a single meal — this triggers muscle protein synthesis more reliably.

03How to put it into practice

1. Roughly calculate your own target: body weight (or normal weight, if overweight) × 1.0–1.5 g as a practical guideline; the pure DGE baseline is 0.8 g/kg, and with intense training or during a diet it's fine to head toward 2.0 g/kg.
2. Spread it across three main meals: instead of loading the day's total into one meal, aim for 25–40 g per meal — this makes better use of both the satiety and the muscle-building effect.
3. Build in good everyday sources: low-fat quark, skyr, eggs, chicken, fish, lentils, chickpeas, tofu, and dairy products each provide roughly 10–25 g of protein per serving.
4. Compare protein per 100 kcal, not just per 100 g: two foods with similar protein per 100 g can look very different once you factor in calories (example below).
5. Keep it deliberately high during a diet: in a calorie deficit, above-average protein intake helps twice over — against hunger, and against muscle loss.

At first glance, Gouda and chicken breast look identical — both give you 23 g of protein per 100 g. But because of the fat content in cheese, it packs more than three times the calories per 100 g. Once you convert to protein per 100 kcal, the picture flips: chicken breast delivers roughly three times as much protein as Gouda. In practice, that means if you need a lot of protein on a limited calorie budget, lean sources like chicken, fish, low-fat quark, or legumes are usually more efficient than fattier protein sources like cheese or cured meats — which aren't bad, they just play a different role on your plate.