Why some people get hangry faster: New study explains mood swings linked to hunger

A routine trip to a playground recently offered an unexpected insight into a familiar human experience: the sharp mood dip that arrives when hunger strikes. “Come on, little fella – we should get going now.” But the young boy, absorbed in digging sand with a new toy excavator, ignored the call. Moments later, laughter gave way to tears – not due to injury, but simple hunger after missing his usual mealtime. 

While the behaviour is common across ages, the term describing it – “Hangry: to be bad-tempered or irritable as a result of hunger.” – only entered the Oxford English Dictionary in 2018. Scientists say that despite the universality of hunger-related irritability, research into how it shapes daily mood has been surprisingly thin.

Now, a new study sheds light on why some people become hangry faster than others – and why others stay level-headed even when running on empty.

The science behind hunger and mood

Hunger has long been studied in animals as a powerful behavioural driver. Food-deprived rodents will climb high barriers or repeatedly press levers to access food. Wild animals are known to roam further and appear restless when energy stores fall.

But researchers from psychology and mental health fields wanted to understand how hunger plays out in everyday human emotions. Their study equipped 90 healthy adults with continuous glucose monitors for a month. These devices, commonly used by diabetes patients, recorded blood sugar every few minutes. Participants could also check their own readings via an app.

In addition, each person completed twice-daily mood surveys, noting hunger levels on a scale of 0 to 100 and rating their emotional state.

What the study uncovered

The team found that blood sugar alone did not predict irritability. Instead, participants were in a worse mood only when they consciously recognised they were hungry.

A second key finding was that individuals with higher interoceptive accuracy – the ability to sense internal bodily signals – experienced fewer mood swings. These people were not less hungry; they were simply better at managing their emotional state when hunger occurred.

Interoception acts as the psychological bridge between the body's energy status and a person’s mood. Hunger signals start in the hypothalamus and reach conscious awareness through the insula, a brain region involved in taste and emotions. Those better attuned to these internal cues appear more resilient to the mood dips commonly associated with hunger.

Researchers say this matters because sudden irritability can strain relationships, cloud judgement and encourage impulsive decisions – including grabbing quick, unhealthy snacks. Over time, failing to listen to the body's needs may stress both mental and physical health systems.

Why children melt down – and adults get caught off-guard

Young children, whose bodies and brains are developing rapidly, struggle to recognise early signs of hunger or thirst. Their focus on play and surroundings often overrides physical cues, making sudden emotional outbursts more likely – such as the playground episode described earlier.

Adults, too, can miss early hunger signals in a world full of digital distraction and irregular routines. Skipping meals or delaying food intake can trigger unexpected energy dips that quickly sour one’s mood.

Can people reduce hangriness?

According to the researchers, interoceptive skills can be improved. Regular physical activity strengthens the body’s energy-regulating systems and sharpens awareness of hunger cues. Keeping consistent meal timings is another simple strategy to prevent unexpected drops in energy.

While hunger is only one of many factors influencing mood, the study suggests that paying closer attention to internal signals can help people maintain steadier emotions throughout the day.

For the parent in the playground, the takeaway was clear: anticipate hunger before it erupts. For the rest of us, staying ahead of “hangry” moments may be as simple as tuning in to what our bodies are trying to say. (The Conversation)