A scientific study has finally given credence to what many people intuitively know: never go shopping on an empty stomach. Associate Prof Tim Crowe discusses these findings.
Fasting or food deprivation in a restrictive diet is well-known to increase both the quantity and quality of food a person eats when they break their fast or diet. It seems logical, then, that this would explain why advice is given to people trying to eat less to avoid shopping when hungry. Surprisingly though, the area of hunger and shoppers’ purchases hasn’t been well studied.
Do people really buy more when they are hungry and are they more likely to choose high-kilojoule foods compared to someone shopping on a full stomach? Researchers from Cornell University set out to study this serious gap in the dieting folklore mythology to see if there may be a kernel of truth to it.
Sixty eight adults took part in the study which was designed in the first part to be a lab experiment. Each person was asked to not eat for 5 hours before the late afternoon experiment kicked off. Just before the participants were let loose on the online simulated grocery store, half of the people were given some wheat biscuits to curb their well-developed hunger. The online store offered a variety of consumer staples as well as plenty of salty and sugary energy dense snacks.
People who hadn’t eaten any food in the afternoon were more likely to choose high-kilojoule foods when they were set loose in the simulated supermarket. Compare that against people who were given a snack before shopping: they bought less of the energy dense foods.
Interestingly, both groups of people bought an equal amount of the low-kilojoule food staples. So the hungry shoppers not only bought more food, but specifically more of the snack types.
Rather than just using a simulated supermarket, the researchers also looked at patterns in shopping purchases in real supermarkets. Shoppers were more likely to buy a greater amount of energy dense foods in the hours leading up to dinnertime of 4 to 7 pm compared to earlier in the day in the hours of 1 to 4 pm.
Details of the study can be found in JAMA Internal Medicine
What it all means
Hungry shoppers are more susceptible to buying energy dense foods, which is not helped by the way supermarkets are cleverly designed to make us buy more at every turn. One way to fight back against this is to either shop soon after meals, or enter the supermarket after chowing down on a healthy snack.