Outliers: This just in: Don't buy groceries when hungry

Science has spoken: Enter a grocery store on an empty stomach at your peril. You are more likely to buy foods with a high calorie count than more healthy options when you're hungry, according to the results of a study published by JAMA Internal Medicine.

Even the journal's editor concedes it's a bit of shopworn guidance. “I think all diet guides include the advice to 'never go grocery shopping when you are hungry,' ” begins an editor's note from Dr. Rita Redberg.

The study used simulated shopping to compare purchases made by those who had eaten and others with an appetite. More candy, snacks and other high-calorie food went into the virtual shopping carts of those who had not eaten for five hours than participants who snacked before shopping. Researchers also tracked actual grocery purchases by 80 study subjects during the hours after lunch and around dinner time. Shoppers during the usual dinner hours of 4 to 7 p.m. also bought more high-calorie food.

“Even short-term food deprivation can lead to a shift in choices such that people choose less low-calorie, and relatively more high-calorie, food options,” wrote Aner Tal and Brian Wansink of Cornell University.

For Tal, a research associate at the university's food and brand lab, knowledge that a missed meal can undermine good food choices does not equal immunity. He can stop at the grocery store on the way home from work. “I buy more packages of chips and ice cream, and later I'm surprised how they end up there,” he says.

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