A recent study conducted by Aner Tal and Brian Wansink from the Food and Brand Lab at Cornell University suggests that people don’t just buy more when they grocery shop on an empty stomach; people go for high-calorie foods not present on their shopping list. For the purpose of the study, which was published in the digital version of JAMA Internal Medicine, higher-calorie foods consist of candy, red meat and salty snacks while lower-calorie choices include chicken breast, fruits and vegetables.
What’s the reason for this phenomenon?
What makes everything look good enough to eat right then and there when you grocery shop on an empty stomach? Tal and Wansink’s research team suggested that psychological and physiological responses are to blame.
Your bodily functions don’t understand the difference between skipping a meal and a famine. When you diet by fasting and starving yourself, your body enters survival mode because it doesn’t know if food will be scarce from now on. That means, when you start selecting foods on an empty stomach, your body directs you toward higher-calorie foods to replace the calories you haven’t been eating and to stock up in case of another famine.
To prove the point that psychological and physiological responses cause higher-calorie food to be more tempting on an empty stomach, researchers conducted two experiments. The first took place in the lab while the other involved following actual shoppers around.
In their first experiment, researchers sought to discover if having a snack before shopping for food could tip the scale toward picking healthier, lower-calorie choices off the shelves.
Researchers told 68 participants to refrain from eating for five hours leading up to the study. Before testing began, the researchers gave some participants crackers to ease their hunger. Then, the participants “shopped” in an online grocery store.
Those who received a snack tended to choose lower-calorie options, such as low-fat ice cream over regular ice cream.
In the second experiment, researchers followed 82 participants as they shopped. Just like the lab experiment, the results showed that people tended to purchase higher-calorie foods when they were hungry compared to those who had eaten recently.
While these studies are very small-scale, they show that skipping meals as a weight loss effort, then shopping on an empty stomach, can backfire. To prevent inadvertently filling your pantry and fridge with unhealthy food, be sure to eat healthy meals and snacks at regular intervals throughout the day. This signals your body that food is readily available and there’s no need to go into survival mode. By choosing healthy foods, monitoring your portions and getting daily exercise, you set yourself up for a happier, healthier body and mind.