Having coffee before shopping may impact what you buy and how much you spend: study

Espresso is seen in this file photo. (Unsplash)

If you're trying to cut back on non-essential purchases, researchers say you may want to hold off on drinking caffeine before heading to the store.

A new international study led by the University of South Florida (USF) has found that drinking coffee before going shopping can impact what products consumers choose to buy, as well as how much they spend.

"Caffeine, as a powerful stimulant, releases dopamine in the brain, which excites the mind and the body. This leads to a higher energetic state, which in turn enhances impulsivity and decreases self-control," said lead author and USF professor Dipayan Biswas in a press release.

"As a result, caffeine intake leads to shopping impulsivity in terms of higher number of items purchased and greater spending."

The findings were published Thursday in the peer-reviewed Journal of Marketing.

According to the study, researchers conducted various experiments involving an espresso machine at the entrances of a retail chain and home goods store in France and a department store in Spain.

Upon entering the stores, 300 shoppers were offered a complimentary beverage. According to the study, about half of patrons were offered a cup of coffee that contained roughly 100 mg of caffeine, while the other half were either given decaffeinated coffee or water.

Upon exiting the stores, shoppers then shared their receipts with the researchers.

The study found that those who drank caffeinated coffee prior to shopping purchased a "significantly higher" number of items and spent more overall compared to those who had decaf or water.

According to the report, caffeinated individuals spent about 50 per cent more money and bought nearly 30 per cent more items.

The study also found that caffeine impacted the types of items shoppers purchased.

Researchers reported that those who had coffee bought more non-essential goods, such as scented candles and fragrances, compared to the other group of shoppers.

However, the study noted that there was "a minimal difference" between the two groups when it came to practical purchases or necessities, including kitchen utensils and storage baskets.

Researchers conducted another experiment in a lab setting, this time looking at online shopping habits.

In this experiment, researchers divided 200 business school students into those who consumed caffeinated coffee, and those who drank decaf. The students were then asked to pick which items they would purchase from a predetermined list of 66 options.

The study found that those who drank caffeine selected a greater number of products that would be considered impulse purchases, such as a massager, while the other group tended to select more practical goods, like a notebook.

Given the results, the study's authors suggest consumers avoid drinking coffee before shopping if they're trying to keep to a tight budget.

"While moderate amounts of caffeine intake can have positive health benefits, there can be unintended consequences of being caffeinated while shopping," Biswas said in the release.

"That is, consumers trying to control impulsive spending should avoid consuming caffeinated beverages before shopping."