Protein Shakes for Teens: What Nutrition Experts Say About Need, Risks and Value

A teenager weighing 45 kilos needs about 40.5 grams of protein a day, according to the German Nutrition Society, known as the DGE. That is roughly what a day of oat flakes with almond drink, a baked potato with curd cheese, and wholemeal bread with peanut butter can supply. The figure matters because protein powders, bars, puddings and breads are increasingly pitched at young people as a route to muscle, weight loss and healthy growth.

The pitch appears to work. A representative University of Michigan survey of almost 1,000 parents, conducted in 2024, found that just under half said their children, aged 13 to 17, had used protein products in the previous year. Boys were more likely to use them, usually for sport or to build muscle. Girls more often used them to balance their diet or lose weight. In Germany, the statistics portal Statista recorded a jump of around 25% in retail revenue for fitness protein products between March 2024 and March 2025. Products such as Kindershake and Teen Balance are designed specifically to appeal to younger buyers.

Proteins are building blocks for the body. They build and repair tissue in muscles, skin and organs, and they form the enzymes that regulate chemical reactions and the antibodies the immune system depends on. The DGE recommends 0.8 grams per kilo of body weight daily for healthy adults, so a 65-kilo woman needs 52 grams. Young people, who are still growing, are advised to take 0.9 grams per kilo. People over 65 and children aged one to four should have one gram per kilo.

Most young Germans already exceed that. A German study from 2015 to 2017 found that around half of six- to 17-year-olds ate more than double the recommended amount. Older people are the group more likely to fall short, often because their appetite declines.

The DGE says excess protein can do harm over time. Studies show children who eat too much, particularly animal protein, often become overweight, and some enter puberty early. The kidneys are the main concern: they must convert the amino acids in protein into urea before it leaves the body in urine, and heavy loads can strain and damage them. The risk rises if someone drinks too little or already has kidney damage, though adolescents are also at greater risk.

Active people do need more. A DGE position paper says protein can help maintain or build muscle mass and strength and support recovery. It puts the range for sportspeople at 1.2 to 2 grams per kilo, spread over several portions through the day, but says this applies only to people who train more than five hours a day. Protein also satisfies hunger, and people on protein-rich diets usually lose more weight than on others, though over the long term the balance of calories eaten and burned is what counts.

On sources, plant proteins generally contain somewhat fewer essential amino acids, the ones the body cannot make itself. But wholegrains, pulses and nuts also bring fiber, vitamins and unsaturated fats, so the DGE advises raising protein intake mainly through plant sources.

Criticism of the products is broader. Powders and bars are often loaded with sweeteners, sugar, additives and flavorings, and the German Sport University in Cologne found doping substances in some products sold for muscle building. Powders are usually made from milk proteins, which can raise the skin's sebum production and may trigger or worsen acne, although a direct link has not been definitively proven. Specialists also worry that shakes replace regular meals, cutting fiber, micronutrients and healthy fats.

Cost is another factor. A 2022 study by consumer organizations found that naturally protein-rich foods such as cheese, curds or soya drinks often cost more when the manufacturer highlights the protein content. The DGE says even athletes should meet their needs by optimizing their diet, and that there is no scientific evidence that bodies under strain require protein supplements. Experts see a case for protein preparations only for people with allergies, problems with digestion, chewing or swallowing, or very low appetite.