Scientists have determined that the body senses a deficiency of essential amino acids and sends a signal to the brain about this, resulting in an increased desire in humans for protein-rich foods.
Medianews.az reports that this was noted in a new study published in the journal “Science.”
According to the research, protein hunger differs from ordinary hunger. The body needs not only energy but also essential amino acids that are important for the formation of enzymes, muscles, hormones, and tissues. These substances are not synthesized in the human body and therefore must be obtained through food.
The study was initially conducted on fruit flies. Observations showed that flies lacking protein avoided substances without nutritional value and preferred foods containing essential amino acids. The same tendency was observed in experiments conducted on mice. This indicates that such a mechanism may be a common biological feature across various living organisms.
Scientists have found that a signaling molecule called CNMamide produced in the intestines plays a key role in this process. When essential amino acids decrease, its production increases; the signal is transmitted to the brain via nerve cells and promotes selection of protein-rich foods. At the same time, this molecule enters the bloodstream as a hormone, maintaining the effect of the signal for a longer duration.
The research also showed that during protein deficiency, the body not only increases interest in protein but also reduces the craving for sugar. Although sugar provides energy, it does not replace essential amino acids. To achieve this, the activity of nerve cells in the brain that accept sugar is weakened, and the body prioritizes fulfilling its protein needs.
According to the study's authors, appetite is influenced not only by the feeling of hunger but also by a complex system of biological signals reflecting the body's internal needs. The research demonstrates that sugar and protein, which have the same calorie value, do not serve the same function for the body. The human body requires not only energy but also substances needed to build tissues, and it has specific mechanisms to convey this to the brain.