The right amount of protein — which recommendations make sense?
Do you prefer short & concise facts? Then quickly scroll to the bottom part.
The main nutrient protein, its ideal intake and quantity is a very popular and multi-faceted topic. You can find a multitude of recommendations on this, which can be helpful but also misleading. Regardless of whether one is concerned with building muscle, losing body weight or general nutrition, the intake of the optimal amount of protein remains one of the main challenges. In the following, scientific data will be used to illustrate what is important in optimal protein intake.
Different interpretations of the correct amount of protein
In order to keep track of the various recommended amounts, it is essential to understand how a specific recommendation is made. Every single one of us consumes important proteins to supply our own bodies with essential amino acids. Through the intake of these vital building blocks, the amino acids lost in our own biochemical body cycle are made up for. Accordingly, the daily intake of proteins is determined by the amount of amino acids irreversibly lost in one day through the body’s own metabolism. Standardised quantity recommendations are always based on the premise of preventing a state of deficiency with regard to essential amino acids. The aim is to maintain a balance between the supply and breakdown of this substance.
Our biological system is therefore dependent on replenishing the minimum amount of protein after the necessary protein building blocks have been consumed. This minimum balance between ingested and degraded proteins is 0.5 g/kg body weight per day. If the focus is on physical performance, this amount of protein is not sufficient. The German Nutrition Society recommends 0.8 g protein per kg body weight for people aged 19 to 65. People over 65 should increase this to 1.0 g. For infants, children and adolescents, separate, individual suggestions apply: Infants up to 6 months of age have an increased requirement of about 2.0 g/kg daily. Adolescents should be guided by the value of 1.0 g/kg daily.
How should strength athletes and athletes behave?
The assumption of an increased protein intake for strength athletes is widespread. The reason for this is purely biochemical and physiological. On the one hand, increased physical exertion leads to increased protein catabolism, and on the other hand, an increased number of amino acids is required to build up muscle proteins. The study situation regarding the daily protein recommendation for strength athletes must be assessed quite critically. Individual studies are subject to special implementation criteria, which are likely to be different in the everyday life of strength athletes. Consequently, a large number of studies advise strength athletes to consume more than the daily dose recommended by the German Nutrition Society. Here, too, different maximum values are in circulation. As a guideline, 1.3 to 1.8 g per kg body weight per day can be established. This benchmark should be completely sufficient for the vast majority.
The timing of protein intake is often brought into play in this context. The majority of athletes supplement their protein intake in the immediate vicinity of the sports session. Studies show that the time of intake has no significant influence on muscle hypertrophy. Instead, the primary goal should be to distribute the amount of protein throughout the day.
Can too much protein intake damage the kidneys?
Advantages and disadvantages must always be weighed when setting up an individually suitable amount of protein. Experience has shown that people with kidney damage can further weaken their kidneys with increased protein intake. It is assumed that this can even lead to kidney stones, given the disposition of those affected. Evidence as to whether excessive protein consumption can impair the work of the kidneys even in healthy people is controversial and, when considering the available studies, partly contradictory. There are currently no sufficiently significant data to support the recommendation to link increased fluid intake to increased protein consumption.
More protein = more vitamin B6?
Many assumptions also point to a compellingly increased need for vitamin B6 after increased protein intake. B6 undoubtedly plays an important role in the metabolism of amino acids. According to the current data, however, it is not necessary to adjust the vitamin B6 requirement upwards due to an increased protein intake, as long as one eats a balanced mixed diet.
5 facts at a glance:
1. Added proteins compensate for broken down proteins in the body
2. There are specially defined recommendations for the daily protein dose for each age group.
3. Strength athletes should definitely consume more protein
4. Based on current studies, high protein consumption only harms the kidneys if the person has a weakened kidney.
5. As a rule, people with increased protein intake should not deliberately take more vitamin B6
Text sources:
(1) Schmidt, Physiology compact, 1999
(2) Wischmeyer et al, Physiology, 2010; https://www.dge.de/presse/pm/wie-viel-protein-brauchen-wir/ (14 April 2020)
(3) Aragon and Schoenfeld, How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution, 2018
(4) Phillips and van Loon, Dietary Protein for Athletes: From Requirements to Optimum Adaptation, 2011
(5) Cuenca-Sanchez et al, Controversies Surrounding High-Protein Diet Intake: Satiating Effect and Kidney and Bone Health, 2015; Kamper and Strandgaard, Long-Term Effects of High-Protein Diets on Renal Function, 2017.
(6) https://www.dge.de/index.php?id=1138; Ernährungs Umschau 2/08, p. 106 f.
Image sources:
(7) Designed by Freepik
