Feeling hungry can modulate our mood. Various research has shown that hunger can make us more negative, more irritable and even more aggressive. The emotional impact of hunger can even have an effect on our decisions. This was demonstrated by a 2011 Israeli study that gave its name to what is known as the “hungry judge effect.” What the study’s authors saw is that the severity of the sentences handed down by judges became harsher as lunchtime approached, and then became significantly more lenient after the meal and rest break. This close relationship even led to the invention of a term in English to refer to this phenomenon, hangry —a combination of hungry (hungry) and angry (angry) —, which sneaked into the Oxford Dictionary in January 2018.
The explanation that has traditionally been given for this relationship has been purely physiological. “Various studies suggest that aggressiveness does not arise spontaneously, but is modulated by the energy availability of the brain and by previous nutritional experience. Self-control—key to inhibiting aggressive behaviors—consume large amounts of glucose, so when it is scarce, or its metabolism is altered, the ability to regulate impulses decreases,” explains Marta Garaulet, professor of Physiology and Physiological Bases of Nutrition at the University of Murcia.
This relationship, the expert maintains, is not exclusive to our species: experimental studies on fruit flies, for example, have shown that food deprivation for more than a day significantly increases aggressiveness among males, even when their physical condition worsens. “In this case, hunger increases the value of the food resource and the motivation to defend it, which translates into more conflicts and confrontations, showing that the so-called phenomenon hangry “It has deep biological roots shared between species,” argues Garaulet.
And, as research with fruit flies shows, not eating is not only a discomfort, but also a biological threat. When blood glucose levels drop, the body activates the stress axis (hypothalamus-pituitary-adrenal), which causes the release of cortisol: “In evolutionary terms, the message is clear: there is a lack of energy, we must react.” As the chrononutrition expert adds, cortisol has an adaptive function: it increases available glucose in the blood, mobilizes energy reserves and keeps the brain “on alert.” The problem is that, at the same time, it reduces non-priority functions such as empathy or emotional regulation, facilitates defensive, impulsive or aggressive responses and makes us interpret the environment as more hostile.
“Cortisol does not cause aggression on its own, but it lowers the threshold at which we react with anger or violence. In combination with a lack of glucose and reduced self-control, it explains very well why hunger makes us more susceptible to conflict,” he reflects.
Beyond the physiological explanation
Once these physiological bases of the relationship between hunger and worse mood are accepted, various investigations are trying to find explanations that go beyond the lack of glucose and the increase in cortisol levels. A study published in 2018 in the journal Emotionfrom the American Psychological Association, asked whether those negative sensations caused by physiological changes induced by hunger could, in turn, bias our perception of the world around us. Based on three experiments, in which they systematically manipulated people’s hunger levels, contextual cues, and their self-awareness, the authors found that simply being hungry was not enough to make someone become hangrybut there are two key ingredients that influence it.
“First of all, you have to find yourself in a negative or unpleasant situation. People don’t seem to get so hangry in neutral or pleasant contexts. If you’re having a good time with friends but are hungry, you probably won’t become irritable unless something annoying or uncomfortable happens. But if you are in an unpleasant or irritating situation, such as a kilometer-long traffic jam, and you are also hungry, then it is a perfect scenario for those feelings to arise,” Jennifer MacCormack, assistant professor in the Department of Psychology at the University of Virginia (USA), explains to EL PAÍS.
Secondly, he adds, self-awareness is essential. According to the researcher, people become hangry when they allow themselves to be absorbed by what is happening around them (traffic, for example) instead of recognizing that the true source of their negativity is hunger. “When we asked participants to pay attention to their emotions in our studies, the bias hangry It disappeared: they stopped being so harsh or critical with others and they even said they felt less irritable and angry despite being hungry,” he explains.
Another recent study, published at the end of 2025 in eBioMedicine (The Lancet), which combined four-week continuous glucose monitoring with recordings that participants completed twice daily at home. smartphone assessing how hungry or full they felt, as well as whether they were happy or sad. With this information, the authors confirmed, as they expected, that lower glucose levels were associated with worse mood. However, what they observed is that this association was also explained by the hunger ratings collected. “In other words, participants were only in a worse mood when the lack of energy was consciously perceived as hunger, not due to a subconscious lack of glucose as an energy source,” explains Nils Kroemer, researcher at the Department of Psychiatry and Psychotherapy at the University Hospital of Tübingen (Germany) and professor of medical psychology at the University of Bonn.
The authors, in fact, found that some people were more sensitive to feeling hangry. Others were also better able to perceive hunger in line with changes in glucose levels and therefore reported fewer fluctuations in their mood. “This suggests that being more aware of body signals can improve emotional regulation by helping to control mood swings more effectively,” he reflects.
Based on the results of these studies, both researchers point out that feeling hangry It is something that can be modulated by being aware that you are hungry and that this is biasing the way you see the world. “Our data suggest that hungry people are not wild beasts: when we recognize the true source of our negative emotions, we can avoid acting impulsively under the influence of that state,” says Jennifer MacCormack.
The University of Virginia professor recommends, in these situations, “try to focus on positive aspects of the environment and put yourself in a more pleasant situation until you can eat something.” For example, in the case of the aforementioned traffic jam, listening to relaxing music. Nils Kroemer, for his part, highlights that it is important to maintain a regular meal schedule, which allows us to avoid unpleasant surprises for the body, since conscious hunger usually appears when we skip a meal that we expected to eat. “If we never eat breakfast, we don’t feel as hungry in the morning as when we skip breakfast on a specific day,” he concludes.
