A new scientific study has shown that emotions such as anger and irritability are closely linked to hunger. The study, published in the journal PLOS ONE, is the first to look at how hunger affects people's emotions on a daily basis.

A new study led by scientists from Ruskin University in the UK and Karl Landsteiner University in Austria has found that hunger is associated with increased levels of anger and irritability, as well as decreased levels of pleasure.

The researchers recruited 64 adult participants from Central Europe who recorded their hunger levels and various measures of emotional well-being for 21 days.

Participants were asked to report their feelings and hunger levels on a smartphone app five times a day, allowing data to be collected in everyday settings such as the workplace or at home.

The results showed that hunger was associated with greater feelings of anger and irritability, as well as lower pleasure scores, and this effect was significant even after adjusting for demographic factors such as age and gender, body mass index, eating behavior, and personality traits.

Hunger was associated with 37% variance in irritability, 34% variance in anger, and 38% variance in pleasure reported by participants. The study also showed that negative emotions - irritability, anger and unpleasant feelings - are caused by both daily fluctuations in hunger and residual levels of hunger, as measured by averages over a three-week period.