Want an extra serving of protein? Millions of people say "yes". Not only active athletes reach for protein shakes as a matter of course. Concerned parents are also increasingly providing their children with extra protein via fortified cornflakes or smoothies, because they need to be properly fed. Sensible or not? That's what science says.
Before we clarify whether and why we need protein shakes, let's take a look at the nutrient itself. Along with carbohydrates and fats, protein is one of the three macronutrients that are vital for us humans. They form the foundation of human metabolic processes and are essential for life.
If the intake of protein is missing, deficiency symptoms such as weakness and dizziness occur.
If one follows the calculations of the German Society for Nutrition, young people and adults need an average of 0.8 grams of protein per kilogram of body weight per day. This corresponds to 64 grams for a body weight of 80 kilograms.
However, if a lot of sport is done, this requirement can increase significantly. Many experts then assume 1.0 to 1.5 grams of protein per day and kilogram, for active bodybuilders it should be up to two grams. The requirement of an 80kg strength athlete would thus be up to 160 grams of protein per day.
Protein shakes are in principle suitable for everyone who wants to cover their daily requirements. The shakes do not replace a high-quality meal, because it is ultimately a dietary supplement. This is how the shakes should also be used - those who do not practice weight training can easily cover their daily needs with food.
And what does that mean in practice? A sandwich for breakfast, a plate of spaghetti with parmesan for lunch, a light salad with chicken or fish in the evening - the need is already covered.
The bodybuilder would probably have to treat himself to a 350-gram ribeye instead of chicken with his salad - which adds about 100 grams of protein. He also needs carbohydrates for energy and has to watch his overall calorie intake.
Alternatively, for vegetarians, perhaps there would be a lentil stew with tofu sausage. However, with vegetarian foods, it must be taken into account that they provide fewer amino acids essential for muscle building compared to animal products.
Basically, it is important to determine your own protein requirements and to cover them properly. Protein-containing foods are, for example, beef, chicken, eggs, fish, low-fat curd cheese, peas, nuts, lentils, soy and cheese.
The fact that it's not required to add some extra protein in a balanced diet does not mean that taking protein shakes is pointless or even harmful. After all, even foods with a high protein content hardly exceed a protein content of 30 percent, while protein powders have a protein content of up to 85 percent.
Advantages of protein shakes are therefore:
- convenient intake at the desired time
- simple and exact dosage
- precisely defined, comprehensible composition
In addition: The protein supply may be secured in a balanced diet, but the balanced diet itself is often not. Those who take too little time for meals in addition to work and sports are then in doubt about being undersupplied. Especially with athletes, this deficiency can occur increasingly in the area of proteins. Protein shakes then provide a quick remedy.
It is to be differentiated clearly, which kind of sport someone pursues. Whey shakes are indispensable in bodybuilding, but a professional runner does not necessarily need them.
The scientific consensus is that humans need the building block protein to build up body cells, including muscle mass. Studies on the subject therefore deal primarily with the how and when - i.e. the type of intake (powder or natural foods), the type of protein (biological value) and the best time for protein intake (directly to the workout or just regularly).
(Strength) athletes usually take their protein shake immediately before or after training. This is to guarantee that the body uses the protein in the "anabolic phase" to build muscle.
Studies from the USA, done in 2013 with extensive subject testing, do not support this thesis. The US researchers Brad Jon Schoenfeld, Alan Albert Aragon and James W. Krieger found that neither muscle mass nor strength development are influenced by the timing of protein intake.
Comparison values were a maximum 1-hour time window and an interval of at least two hours from training.
The general correlation between the time of protein intake and its effect was not questioned, as the nutrient cannot be stored in the body. A regular, preferably daily, protein intake is therefore necessary regardless of this.
Protein is a component of many foods. It is not only found in animal foods such as meat or milk, but also in plant foods such as vegetables, potatoes and rice. For the human body, however, not all protein is the same, because its breakdown into amino acids takes place (over time) very differently.
Sports medicine professor Petra Platenrecommends at Spiegel Online: "To ensure the best possible muscle build-up, the ingredients of the dietary proteins should correspond to those found in the muscles." It's all about the highest possible "biological value". The higher it is, the more dietary protein can be converted into the body's own protein.
Many animal proteins have a high biological value, but potatoes, rice or soy are also suitable sources. Protein shakes have the advantage that proteins can be combined according to a certain pattern. They can therefore be designed according to the desired effect - for example, according to the criterion of immediate availability.
Generally, the ingredients from food do not always match those from a protein shake. The protein from a casein shake supplies the body for several hours, but contains hardly any vitamin B12 compared to a piece of meat.
An important point is also the price, which is ultimately also the target of criticism by many consumer advocates. When organisations such as "Stiftung Warentest" or "Öko Test" criticise protein shakes, the conclusion is usually: it's not worth it, protein is also available cheaper.
However, it is not: Hands off, you damage your health. Voices in the direction of health protection - for example, the US magazine Consumer Reports - are actually only loud when it comes to the burden of protein powders with heavy metals, whereby concentrates from animal proteins are particularly contaminated.
Whey protein: Extremely fast absorption, the protein is quickly available to the body, but the effect is limited to about three hours. Very high biological value.
Casein (milk protein): Slow absorption, the protein is constantly available to the body over a longer period (up to about eight hours) and is suitable for taking before bedtime. Medium biological value.
Soy protein: Rapid absorption, the first choice for vegans and vegetarians due to its vegetable base. Available up to five hours after ingestion. High biological value.
Multicomponent Protein: Attempts to combine the positive properties of proteins and thus achieves the highest biological value. All-rounder, which also serves as a food substitute.
Leisure and strength athletes particularly appreciate the high protein content with low fat and sugar values, the rapid availability in the body and the positive properties for muscle building, muscle regeneration and weight loss.
New protein shakes hit the market every year. The question remains open: Which provider is particularly convincing?
In 2021, the following five providers have proven to be among the best:
- ESN Designer Whey protein powder
- Weider Protein 80 Plus
- Foodspring Whey Protein
- Bodylab24 Whey Protein
- Bodyworldgroup Master F90
The quality of a good protein powder consists of various criteria. Not only the amount of protein counts, but also the amount of amino acids, the consistency, biological value, price-performance ratio and taste.
Finally, we summarize the most common questions about protein and protein shakes.
Whey is immediately available to the body and is therefore perfect after a workout. Casein is available longer in the body and is best taken before sleeping. Muscles grow during the recovery phase and casein supports this process.
One best product does not exist. Some powders are more popular than others, but not better. Decisive is not only the protein content, but also the amount of sugar and carbohydrates. Popular brands are Optimum Nutrition, ESN and MyProtein.