Shopping on an empty stomach makes you spend more (!)

Next time you go shopping, you might want to line your stomach first.

You’ve probably heard that we tend to spend more money when we go grocery shopping when we’re hungry. It only makes sense that we can’t resist creamy pasta sauces and tubs of Ben & Jerry’s when our stomachs are rumbling. But it turns out that we also spend waaaaaaaay too much when we’re not even buying food.

As New Scientist reports, researcher Alison Jing Xu from the University of Minnesota once had a major case of shopper’s remorse in a mall food court. So she decided to find out if other people also bought stuff they regretted as a result of being hungry.

In one, participants rated their level of hunger, and were then asked to evaluate ten items (five food, five non-food) on the basis of how much they liked and wanted them. The result showed that people were more likely to want and like the food items when they were hungry. But they were also more likely to want the non-food items, even if they didn’t especially like them.

To find out how this compared to a real life situation, Xu and her colleagues went back to the mall. They looked at 81 customers receipts (with permission!) and asked them how long they’d spent shopping and what their mood and hunger levels were like. They found that even when time spent shopping had been taken into account, customers who were hungrier than the median spent SIXTY FOUR PERCENT MORE. (Saving money by waiting to eat until you get home’s starting to look a little silly now, isn’t it?)

Xu blames this lack of self-control on ghrelin, a hormone our stomachs release when we’re hungry. It acts on the reward and motivation part of the brain, making us want to stuff our faces. Her theory is that it makes us want to seek out other kinds of rewards, too. Like shoes.

She and her team are now planning to study how hunger affects how we communicate with others. Just a guess based on personal experience: not well.