A new study offers evidence to support what many people have
learned for themselves: never go grocery shopping when you're hungry.
Researchers found that people who hadn't eaten all afternoon
chose more high-kilojoule foods in a simulated supermarket than those who were
given a snack just before online food shopping. And in a real grocery store,
shoppers bought a higher ratio of high-kilojoule foods to low-kilojoule ones in
the hours leading up to dinnertime compared to earlier in the day, the study
fasts can lead people to make unhealthy food choices," said Amy Yaroch,
head of the Gretchen Swanson Center for Nutrition in Omaha, Nebraska.
"Don't go shopping when you're hungry and you don't have a list, because
you're just going to buy all sorts of junk food," advised Yaroch, who
wasn't involved in the new study.
who cannot buy healthy food
She said the results may have implications not just for
everyday shoppers, but for "food insecure" families, which often
don't have the money to buy healthy food - or any food. For their research,
Aner Tal and Brian Wansink from Cornell University in Ithaca, New York,
conducted a lab study and went out into "the field" to see how hunger
influenced food choices.
For the lab study, they asked 68 adults not to eat for the
five hours before a late-afternoon appointment. Prior to starting the
experiment, the researchers gave half of the participants a plate of Wheat
Thins to sate their hunger. Then they had all study subjects shop in a
simulated online grocery store.
On average, both
hungry and sated participants bought eight low-kilojoule food items, which
included certain types of dairy products, meats and snacks. The hungry
participants also bought six higher-kilojoule items, compared to four purchased
by people who'd recently had a snack, according to the findings published
Monday in JAMA Internal Medicine.
Participants in the
Likewise in their field study, the researchers observed 82
people's purchases in a real supermarket and found the ratio of high-kilojoule
foods to low-kilojoule foods was healthier between 1 pm and 4 pm than between 4
pm and 7 pm.
Endocrinologist Tony Goldstone from Imperial College London
said the findings should be interpreted cautiously given the assumptions the
authors made that people would be hungrier during the later time period.
Still, he told Reuters Health, "It overall is pointing
to what we expected."That behavior might stem from an evolutionary time
when it was essential for a person to find high-kilojoule food after a long
fast, Tal speculated. Goldstone agreed."The body is always trying to
defend its state and it makes very logical sense that if you're going for a
period without food, and you're wanting food, you're more likely to go for the
food that's high-kilojoule," he said.
"If we're needing energy, we're not going to go out for
lettuce."Tal recommended that people have a snack, such as a piece of
fruit, before going grocery shopping or chew gum while perusing the aisles to
mitigate the effects of hunger."Do your shopping at hours when you're less
vulnerable, like after lunch versus before lunch, and so on," he told
Why people go to the
junk food aisle
Yaroch said that for people who can't always afford food,
the new study shows there may be biological cues as well as practical ones
pointing them toward the junk food aisle."It's not surprising to me that
when you're hungry, you're going to choose foods of low nutritional
quality," she told Reuters Health.
"What's disturbing to me is I feel that people don't
understand the connection between obesity and food insecurity." Not
knowing when you're going to have food available means that when you do, you're
going to choose a high-calorie option, Yaroch said - especially when it's the
cheapest one. "There are definitely different implications for someone
who's hungry most of the time," she said.