Prejudices against protein? We're here to educate!

Who hasn't experienced this: You're calmly drinking your post-workout shake when some acquaintance, colleague, or family member starts lecturing you unprompted:

"This artificial stuff can't be healthy!"

"I've heard that protein damages the kidneys!"

"That's completely unnecessary – a normal diet is perfectly sufficient."

These and many other phrases regularly escape the mouths of self-proclaimed nutrition experts. Annoying, isn't it?

The researchers around Jose Antonio probably thought the same thing when they decided to publish a paper entitled "Common questions and misconceptions about protein supplementation: what does the scientific evidence really show?" In this paper, the authors address eleven (more or less) important questions, which we have listed below:

1. Is protein harmful to the kidneys?
   
   To sum it up: No. Despite extensive research, there is absolutely no evidence of impaired kidney function in healthy individuals due to excessive protein intake. The authors even suggest the exact opposite. A high-protein diet is a well-known and effective strategy for reducing body fat and improving body composition. This is particularly desirable for people at increased risk of kidney disease (lipid metabolism disorder, obesity, high blood pressure).
   
2. Does excess protein increase body fat mass?
   
   According to current data, it appears that a particularly high-protein diet (for example, 3.3–4.4 g of protein per kg of body weight) does not lead to an increase in body fat in exercisers. Based on this data, the hypothesis that excessive protein alone increases body fat percentage is questionable. The authors conclude that an increase in body fat is primarily due to the intake of carbohydrates and fats. Protein itself is not the driving force here—it is, unsurprisingly, primarily calorie intake that matters.
   
   
3. Can dietary protein have a lasting effect on bone health?
   
   Both mechanistic data and data from intervention studies and meta-analyses suggest that the opposite is true. Bones consist of 50% protein by weight. Furthermore, protein stimulates the release of the growth factor IGF-1, which plays an important role in bone formation. As we also know, protein contributes to building muscle mass and strength. Stronger muscles, in turn, exert more tensile stress on the bones, which promotes their formation. Medical panels focusing on osteoporosis (reduced bone density) conclude that higher protein intake is associated with greater bone mineralization, slower bone loss, and a reduced incidence of hip fractures in the elderly population. The European Food Safety Authority (EFSA) has also approved the following health claims for protein intake:
   
   Protein is needed for normal growth and bone development in children, and protein contributes to the maintenance of normal bones.
   
   
4. Can vegans and vegetarians consume enough protein to ensure the necessary physical adaptations to training?
   
   Although animal proteins are superior to plant proteins in terms of protein quality, it is possible for vegetarians and vegans to meet their protein requirements. However, they generally need 20-40% more protein to achieve similar levels of essential amino acids (including L-leucine) as people who follow an omnivorous diet.
   
   
5. Are cheese and peanut butter good sources of protein?
   
   The authors consider energy-dense foods like cheese and peanut butter to be poor protein sources due to their high fat content. They recommend consuming these foods in moderation to avoid exceeding individual energy requirements.
   
   While we generally agree, there are training phases with increased calorie requirements where a cheese or peanut butter sandwich can be beneficial. There are also still self-proclaimed "hardgainers" who struggle to consume enough calories. Therefore, everyone should be responsible for assessing their own calorie needs and be able to read nutritional information on product packaging to determine whether cheese or peanut butter are good or suitable protein sources.
   
   In terms of its amino acid profile, cheese, which depending on the type (and water content) contains both casein and smaller amounts of whey protein, represents a high-quality protein source. While peanuts contain all nine essential amino acids, their protein quality is not comparable to the high-quality milk proteins in cheese.
   
   
6. Is meat consumption detrimental to health?
   
   This question cannot be answered definitively, as only data from "observational" studies can be used for evaluation. A randomized, double-blind study on the effects of meat consumption is simply impossible (after all, one would have to feed people a meat-based or meat-free diet under controlled conditions for their entire lifespan (~80 years) and monitor their health parameters at regular intervals).
   
   The authors conclude that processed meat may have negative health effects, but these must always be considered in the context of the effects of other foods and lifestyle factors. White meat and (surprisingly) fish do not increase the risk of cardiovascular disease or various types of cancer. They may even reduce the risk of gastrointestinal cancer (i.e., cancers of the digestive tract). Even the frequently demonized red meat is most likely not responsible for the development of disease.
   
   In answering the next question, the authors cite a study suggesting that 45-60% of protein should come from high-quality animal sources, as vegan protein sources can lead to deficiencies in vitamin B12, iron, calcium, zinc, and omega-3 fatty acids. In our opinion, such factors should also be considered when assessing the health benefits of meat. Furthermore, meat is a source of so-called "meat-based bioactive compounds," including, for example, L-carnitine, creatine, carnosine, chroline, anserine, taurine, alpha-lipoic acid, and coenzyme Q10, which offer a variety of positive health effects.
   
   
7. Do physically active people need protein?
   
   Adequate protein intake is essential for maintaining muscle and bone mass, and, due to the diverse functions of proteins, peptides, and amino acids (e.g., as enzymes, hormones, etc.), it is also crucial for maintaining overall health. Immune function can also be impaired by persistently low protein intake. Furthermore, the authors note that protein intake is the primary factor influencing body composition (the ratio of muscle to fat mass). In conclusion: Everyone needs sufficient high-quality protein – but ambitious athletes naturally require more.
   
   
8. Does protein need to be consumed within one hour to trigger anabolism in the muscles?
   
   The legendary "anabolic window" is something almost every athlete has encountered at some point in their fitness journey. Based on current scientific data, it seems that the total daily amount of protein consumed is more important than the timing of intake. Nevertheless, a post-workout shake still makes sense – after all, it tastes great (especially if it's from WEIDER) and contributes to protein intake. However, you won't lose any gains if you consume protein 61 minutes after finishing your workout.
   
   
9. Do endurance athletes need (additional) protein?
   
   For endurance athletes, building muscle mass is not the primary focus. Carbohydrates and fatty acids are primarily used for energy production during endurance exercise. Only during exertion lasting longer than two hours does the oxidation of amino acids increase. Particularly during prolonged endurance exercise, oxygen deficiency (hypoxia) can lead to damage to the small intestine (leaky gut). Both the increased amino acid oxidation and the damage to the small intestine can ultimately result in a negative protein balance.
   
   Furthermore, protein (in combination with carbohydrates, compared to carbohydrates alone) can accelerate the replenishment of glycogen stores. Support for the immune system and accelerated regeneration are also of great importance for endurance athletes.
   
   So, dear endurance athletes, don't be fooled by the man with the mustache and impressive biceps on our products. You can benefit from our delicious shakes just as much as any strength athlete!
   
   
10. Are protein supplements necessary to meet the increased protein needs of athletes?
    
    Protein shakes are certainly not essential, as it's quite possible to meet your protein needs with meat, fish, dairy products, eggs, and other protein-rich foods. In practice, however, it's not always easy to reach approximately 2.2 grams of protein per kilogram of body weight.
    
    It should also be noted that protein shakes are regular food products and not dietary supplements. The proteins from milk (casein and whey), which are among the highest quality protein sources available, are isolated and enhanced with flavorings and sweeteners to create our outrageously delicious protein shakes.
    
    Protein shakes are delicious, convenient, and nutritionally excellent!
    
    
11. Is there an upper limit to how much protein can be consumed per meal?
    
    The essential amino acid (EAA) content of a protein source is crucial for stimulating muscle protein synthesis, i.e., muscle growth. As already mentioned in the answer to question 4), most plant-based protein sources are inferior in this respect, meaning that a larger quantity must be consumed to achieve the same EAA content as animal proteins.
    
    Approximately 20 g of high-quality protein is sufficient to stimulate muscle protein synthesis in young adults. Higher amounts have proven beneficial during periods of calorie deficit, such as dieting, or during particularly intense training phases. A recent study shows that even large single doses (in this case, 100 g of protein) are absorbed and can stimulate muscle protein synthesis for more than 12 hours. In fact, the anabolic response (muscle growth) was higher with a single 100 g dose than with a 25 g dose. These data challenge the previous assumption that consuming approximately 40 g of protein results in maximum stimulation of muscle protein synthesis.
    
    There is no known upper limit to the benefit of a single, high protein intake. Based on the latest study results, it cannot be ruled out that this limit is even higher than 100 g of protein.

Thanks to Jose Antonio and colleagues, after reading this article you will be optimally equipped to put the know-it-all faction in their place during the next nutrition debate.

With this knowledge in mind, the protein shake tastes twice as delicious.