Your body needs proteins to function properly, for instance to build, repair and maintain muscle tissue, to drive metabolic processes and to provide the amino acids used to produce and regulate hormones.
Where do we get them? One way is via animal sources such as meat, fish, dairy products and eggs, nutritionists say. Some plant foods are rich in protein too, including soya and other beans, lentils, peas, pumpkin seeds, quinoa and whole-grain products such as oat flakes.
It's important to know though, particularly if you follow a vegetarian or vegan diet, that animal and plant sources aren't equal when it comes to the quality of protein they provide, points out nutrition expert Katharina Holthausen.
The difference lies in their composition of amino acids, the building blocks of the complex molecules that are proteins. Your body needs 20 different kinds of them, nine of which - called essential amino acids - it can't make itself and must come from the food you eat. Complete proteins have all nine.
"Most animal foods deliver all of the essential amino acids," Holthausen says, but plant foods - with the exception of soya, quinoa and buckwheat - don't. So "to meet your amino acid requirements with plant foods, it's advisable to combine various protein sources."
A good combination is grains and legumes, which include beans, peas, lentils and peanuts. Grain products contain certain essential amino acids that legumes don't, and vice versa. "They complement each other perfectly," says Holthausen.
While pairing them in meals might seem complicated at first, often it isn't at all. If, for example, you make yourself lentil Bolognese with whole-grain pasta, or eat pea soup with bread, you've got it right.
You don't have to combine incomplete protein sources with every meal, by the way. It's fine if you spread the variety over the course of the day.
As regards the amount of protein you should eat, the German Nutrition Society (DGE) recommends a daily intake of 0.8 grams per kilogram of body weight for adults between the ages of 19 and 64. So if you weigh, say, 75 kilograms, you should try to eat about 60 grams of protein daily.
If you're aged 65 years or older, you should have a little more protein in your diet. The DGE then puts your daily protein requirements at 1.0 grams per kilogram of body weight. Athletes who train at least five hours a week would also do well to eat more protein.
For some idea of how much protein plant foods contain: A portion of tofu (100 grams) has 16 grams of protein, 200 grams of cooked whole-grain pasta has 12, and a slice of whole-grain bread (50 grams) 3.5.
High-protein products - be it pudding, semolina porridge or a protein drink - aren't necessary, according to nutrition experts, since in most cases a balanced diet will cover your daily protein requirements.
What's more, they're usually highly processed and contain artificial sweeteners or added sugar along with food additives and flavourings, as the consumer advice centre in Hamburg, Germany, found in a 2025 product check.