Recent research cast doubt on the nutritional value of protein bars, suggesting that these snacks may not be as beneficial as consumers believe. A study published in Scientific Reports found that only 47% of the actual protein content of the products is utilized by the body. This means that not all the protein a bar claims to have can be used efficiently, challenging the perception of protein bars as an ideal solution for meeting daily protein intake needs.
Protein bars have become increasingly popular among fitness enthusiasts as a means of ensuring easy and quick protein intake. With colorful packaging and promises like "high protein content," they attract consumers who may not always read the ingredients. However, a glance at the label reveals the warning: ingredients like glucose syrup, maltitol, vegetable fat, flavorings, and emulsifiers are common in protein bars, and they may hide more than what the labels show.
Researchers believe the danger of protein bars lies primarily in the fact that these products are often ultra-processed foods. Regular consumption of processed meats and ultra-processed foods may increase the risk of developing colorectal cancer. According to the NHS (British National Health Service), excessive consumption of such processed foods may be associated with obesity, type 2 diabetes, and heart disease.
The study found that "although most protein bars are labeled as 'high in protein,' their protein nutritional quality could be very low according to DIAAS." The researchers simulated digestion using a laboratory method known as Infogest. They classified protein bars into four groups based on the origin of their proteins: only plant-based (pea and rice), only animal (milk proteins), mixed animal (milk and egg) and plant (soy), and mixed animal (milk and collagen) and plant (soy).
Protein mixed with other ingredients can be more difficult to digest than when it is alone. According to the authors of the study, the efficiency of the product can be affected by "the application of lower nutritional quality proteins (such as collagen) and other ingredients, such as carbohydrates, fats, and fibers, that could deteriorate the bioaccessibility of essential amino acids." The best options for protein bars use whey and casein proteins (from milk), while bars made with rice or pea proteins had a lower level of absorption by the body.
"It is important to consciously choose the protein source when consuming protein bars, especially given the many options in the market that can make it confusing to choose the best one." Protein bars can be effective supplements for supporting muscle building and quick protein intake and are a practical option to provide that extra protein needed to reach sports goals.
However, nutritionists warn about the content of protein bars. "The protein bar will not have only whey protein, unlike whey. The ingredient list of the protein bar is usually very large and has many added ingredients," said Marcela Miracca Lage, a nutritionist and member of the Instituto Perin. Lage explains that while a good whey protein will have, on average, 150 calories with a good dose of protein and a very low amount of carbohydrates and total fat, a protein bar can reach 400 calories (or more), with 20g to 30g of carbohydrates per serving and 10g to 20g of fat.
"In terms of calories, many protein bars are comparable to chocolate bars, mainly due to the sugars and fats added to improve flavor and texture," said Thays Pomini, a nutritionist. Pomini warns: "These additives are used to prolong shelf life and improve palatability, but they also mean that the product is highly processed in relation to the ingredients in their natural state." This includes modified ingredients, such as artificial sweeteners, stabilizers, and preservatives.
Experts say the best strategy is still to consume a variety of natural, protein-rich foods. Recommended natural protein sources include chicken breast, lean beef, fish, eggs, and plant alternatives like beans, lentils, and quinoa. These natural protein sources are recommended not only for their protein content but also because they provide other valuable nutrients that improve health and strengthen the immune system.
Protein bars are not necessarily harmful if consumed in moderation. They can have a place in a balanced diet but cannot replace main meals. They should be used only as a supplement, paying attention to the dangers of protein powders. "The consumption of protein bars as part of a complete diet" is suggested, emphasizing that while they can be a practical and ideal option as a pre-workout snack, they should not be relied upon as the sole source of protein.
The preparation of this article relied on a news-analysis system.