You’ve probably heard the age-old warning: Don’t grocery shop when you’re hungry. At least, not unless you want to end up with a cart full of splurge purchases on food. Saving money while grocery shopping might not come naturally to you — though there are some smart tricks to make saving easy. So you might be avoiding the supermarket until after you’ve had a meal. But is the old adage actually true?
It’s hard to say. The phenomenon has been investigated in studies — but never actually proven.
The belief that people buy more food when they’re hungry seemed to gain some credence due to a 2013 study published in JAMA Internal Medicine. The researchers asked 68 paid participants to fast for five hours. Then they were told to go play a computer game that simulated buying groceries. Approximately half were fed some Wheat Thins directly before the simulated shopping excursion, while the other half was kept hungry.
To the surprise of many, the results showed that the two groups actually bought comparable quantities of food. There was, however, a difference in the quality of the foods added to their carts. Hungry shoppers bought more high-calorie foods, many of which were processed snacks and candy. Satiated shoppers tended towards lower-calorie foods such as fruits and fresh vegetables.
Due to these results, many believed that a smart weight loss technique was to eat before going to the grocery store. But (as frustrated dieters probably discovered) this advice isn’t as sound as it seems.
The famous study has since been retracted. One of the researchers was Brian Wansink, whose methods and integrity were called into serious question starting in 2017; as a result, 17 of his studies have been discredited (including the one noted above), and 15 more warranted corrections. Widespread criticism of his biased methodology and skewed results eventually led to his forced resignation from his position at Cornell.
So do you buy more groceries when you shop hungry? Maybe, but maybe not. Oddly enough, when your stomach’s growling, you're actually more likely to buy more of anything else.
According to a more recent study conducted at the University of Michigan, people who were hungry were apt to purchase greater quantities of non-food items. The study itself tested the theory with binder clips. Researchers had asked a group of participants how many binder clips they wanted and how much they liked the binder clips after using them. They also asked participants if they were hungry. Though hunger didn't impact how much people liked the product, higher levels of hunger were correlated with a demand for more binder clips.