You probably know that walking into a grocery store on an empty stomach is unwise. Now a new study suggests walking into a mall while hungry is just as bad—at least for your wallet. The study's title sums up the finding: "Hunger promotes acquisition of nonfood objects." Reporting in the journal PNAS, researchers at the University of Minnesota say they conducted five experiments whose results consistently showed an increase in the desire to acquire things when people reported being hungry. In one experiment where the items (in this case, binder clips) were free, the hungry cohort left with 70% more than satiated participants. And even when people had to pay (this time for department store items), the hungry ones spent 64% more.
"It's probably better to feed yourself before any type of shopping, whether you're going on an actual shopping trip or shopping online," researcher Alison Jing Xu tells Smithsonian. "And if you're really hungry, you'd better think twice before purchasing any items at all or you might regret those purchases later." (The study notes that "hunger does not influence how much they like nonfood objects.") New Scientist reports Xu was inspired by a shopping trip of her own, during which she bought 10 pairs of tights on an empty stomach, "not just the two I needed." She says ghrelin, a hormone released by the stomach that makes people seek out food, may also affect other behaviors. (Doctors are puzzled by a boy who's never hungry.)