Why Does Alcohol Make You Hungry?

Whether it's a few slices of pizza on the way home from a night out or a greasy breakfast to cure an early morning hangover, it's no secret that alcohol triggers the munchies. Now, new research published in the Californian Journal of Health Promotion has revealed why drinking goes hand in hand with hunger cravings.

Led by a collaborative team of North American researchers, the study set out to uncover the link between being drunk and getting the munchies, a term that's been dubbed “the drunchies” by college students.

The mystery behind the “the drunchies”

After analysing the results of an anonymous online survey completed by almost 300 students, the team noted that all alcohol drinkers were more likely to consume fatty, salty or unhealthy foods before going to bed. Furthermore, they were less likely to drink water which adds to the risk of dehydration and can worsen hangovers. The morning after drinking, participants admitted to skipping traditional breakfast options in favour of junk food.

According to lead researcher Jessica Kruger, these dietary habits are spurred by a rise and fall in the amount of blood glucose in the body, which can send hunger pang signals to the brain. Kruger muses that the trend towards choosing salty and fatty foods could be caused by physical cravings, or the fact that unhealthy foods are a fast, easy and available option for late-night snacking.

"Salt is essential to living, too much salt could kill you, but our bodies need it to survive," says Kruger in an interview with IFLScience. "We did not explore the biological mechanisms of this, but it could be due to some of the 'hangover cures' or the availability of salty foods while drinking."

A cognitive craving

Previous research supports the theory, with a recent study from the UK's Francis Crick Institute noting that after consuming excess alcohol, mice experience an increase in activity from neurons known as AgRP, located in the hypothalamus region of the forebrain. As well as increasing appetite the neurons actively slow the metabolism and diminish energy levels.

“Our study clearly shows that the main area of the brain responsible for eating (the hypothalamus and its AgRP neurons) is directly affected and excited by ethanol, and that mice respond very strongly to its exposure by overeating for several hours afterward,” explain study co-authors Sarah Cains, MD and Craig Blomeley, MD.

For many scientists, the relationship between drinking and binge eating is a significant contributor to the US obesity epidemic. For a closer look at how food is handled in scientific labs don't miss 'Safe and Efficient Cryogenic Grinding of Food Samples'.