You may want to think about having a snack before you go grocery shopping. According to new research published in JAMA, going grocery shopping on an empty stomach may actually result in more high-calorie food purchases.
Researchers at Cornell University conducted a two-part study. The first part, conducted in a lab, involved 68 participants who were instructed not to eat for five hours prior to the study. Some of those participants were given crackers before going grocery shopping. Those participants who were not given crackers purchased more high-calorie foods from the store, although the number of food items purchased by both groups was the same.
In the second or field part of the study, 82 participants went grocery shopping during times when they were thought to be hungry 4 to 7 p.m. and during times they were thought to be full right after lunch from 1 to 4 p.m. Those participants shopping from 4 to 7 p.m. bought more high-calorie versus low-calorie food items compared to the ones shopping between 1 and 4pm.
Study authors Dr. Brian Wansink an ACSH scientific advisor and Dr. Aner Tal, both from Cornell University, comment that these findings are supported by a previous study of fasting and brain activity, evaluated via PET scanning technology: Fasting participants showed increased activation in brain areas associated with reward, including the ventral striatum, amygdala, anterior insula, and medial and lateral orbitofrontal cortex, in response to high-calorie versus low-calorie foods. If reactivity to high-calorie foods is increased following fasting, it may well be that people would also choose more of those foods relative to low-calorie foods.
ACSH s Dr. Ruth Kava says, It s comforting to see a study like this that comports so closely with our commonsense feelings: unlike all the complex advice we hear about cutting down on calories, this illustrates a simple step that consumers can take to limit the purchase of high-calorie food items and impulse buys. Just don t go the supermarket on an empty stomach.