Scientists have figured out what puts people in an irritable mood when they need to eat.
The word "hangry" – meaning bad tempered or irritable as a result of hunger – was recently added to the Oxford English Dictionary.
Psychologists have now established that being hangry isn't just about having low blood sugar, according to research by the American Psychological Association published in the journal Emotion.
Instead, being hangry is a complicated emotional response which comes about because of a number of factors on top of hunger, including biology, personality and environmental cues.
The study's lead author Jennifer MacCormack, said: "The purpose of our research is to better understand the psychological mechanisms of hunger-induced emotional states-in this case, how someone becomes hangry."
Ms MacCormack, a doctoral student in the department of psychology and neurocience at the University of North Carolina at Chapel Hill, said context and self-awareness were key to determining if a hungry person becomes hangry.
"You don't just become hungry and start lashing out at the universe," explained the study's co-author, assistant professor Dr Kristen Lindquist.
"We've all felt hungry, recognised the unpleasantness as hunger, had a sandwich and felt better.
"We find that feeling hangry happens when you feel unpleasantness due to hunger but interpret those feelings as strong emotions about other people or the situation you're in," explained Dr Lindquist.
The way people interpret those feelings is a key element that the psychologists investigated, with the research team conducted two online experiments involving more than 400 people from the US.
Participants in the experiment asked to state how hungry they were and were shown images designed to produce either positive, neutral or negative feelings.
They were also shown a Chinese pictograph, an ambiguous image which the participants were asked to rate as either pleasant or unpleasant on a seven-point scale.
According to the team, the hungrier participants rated the pictographs negatively only when they had been primed with a negative image.
For hungry participants who had been shown neutral or positive images, there was no negative response.
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"The idea here is that the negative images provided a context for people to interpret their hunger feelings as meaning the pictographs were unpleasant," said Ms MacCormack.
"So there seems to be something special about unpleasant situations that makes people draw on their hunger feelings more than, say, in pleasant or neutral situations."