Feeling hungry really can make us feel "hangry"

New scientific research has discovered that feeling hungry really can make us “hangry”, with emotions such as anger and irritability strongly linked with hunger. Published in the journal PLOS ONE, the study is the first to investigate how hunger affects people’s emotions on a day-to-day level.

Hangry, a portmanteau of hungry and angry, is widely used in everyday language but the phenomenon has not been widely explored by science outside of laboratory environments. The new study found that hunger is associated with greater levels of anger and irritability, as well as lower levels of pleasure.

The researchers recruited 64 adult participants from central Europe, who recorded their levels of hunger and various measures of emotional wellbeing over 21 days.

Participants were prompted to report their feelings and their levels of hunger on a smartphone app five times a day, allowing data collection to take place in participants’ everyday environments, such as their workplace and at home.

The results show that hunger is associated with stronger feelings of anger and irritability, as well as lower ratings of pleasure, and the effects were substantial, even after taking into account demographic factors such as age and sex, body mass index, dietary behavior, and individual personality traits.

Hunger was associated with 37% of the variance in irritability, 34% of the variance in anger, and 38% of the variance in pleasure recorded by the participants. The research also found that the negative emotions – irritability, anger, and unpleasantness – are caused by both day-to-day fluctuations in hunger, as well as residual levels of hunger measured by averages over the three-week period.

What the researchers say: “Many of us are aware that being hungry can influence our emotions, but surprisingly little scientific research has focused on being ‘hangry,’” the lead author told us. “Ours is the first study to examine being ‘hangry’ outside of a lab. By following people in their day-to-day lives, we found that hunger was related to levels of anger, irritability, and pleasure.”

“Although our study doesn’t present ways to mitigate negative hunger-induced emotions, research suggests that being able to label an emotion can help people to regulate it, such as by recognizing that we feel angry simply because we are hungry. Therefore, greater awareness of being ‘hangry’ could reduce the likelihood that hunger results in negative emotions and behaviors in individuals.”

“This ‘hangry’ effect hasn’t been analyzed in detail,” the researchers commented. “So we chose a field-based approach where participants were invited to respond to prompts to complete brief surveys on an app. They were sent these prompts five times a day on semi-random occasions over three weeks.”

This allowed the team to generate intensive longitudinal data in a manner not possible with traditional laboratory-based research. Although this approach requires a great deal of effort – not only for participants but also for researchers in designing such studies – the results provide a high degree of generalisability compared to laboratory studies, giving the researchers a much more complete picture of how people experience the emotional outcomes of hunger in their everyday lives.”

So, what? This research backs up a number of other recent studies which have looked at the effect of glutamate on the emotional and reward systems. Glutamate gets to the brain in a roundabout way from food.

Glutamate is a reward neurochemical but it is also involved in our being open to new ideas and the regulation of mood. The food we eat gives us a certain level of the chemical, which we use between meals. As our glutamate level goes down we become less sociable and open to new experiences and suggestions. We also become more irritable and less ethical. Office and school bullying is often the result of low glutamate levels. Alicia and I have noticed this in professional service firms. A partner spends all day pleasing clients, balancing what is good for the client and what is good for the firm, and “being nice.”

When they come back to the office or finish a series of virtual meetings from home they are frequently in a foul mood, which is often taken out on family or colleagues.

The solution is to do what humans were designed to do: graze during the day on energy-giving snacks such as berries or fruit rather than having three large meals. That way the glutamate levels are maintained, the mood gets better and the bullying and adverse behavior diminish.