Like most people when I go to the supermarket, I pay by credit/debit card but an interesting study published recently in the Journal of Consumer Research suggests that if I wanted to lose weight, it might be better if I used cash.
Researchers studied the behaviour of 1,000 individuals shopping at the same store over a six month period. Around half the shopping trips involved cash payments, while the other half, which were larger, average spends, were paid for by card. It turns out that when paying for groceries by card, shoppers spent significantly more on impulsive items classified as "vice products" (e.g. biscuits, crisps, chocolate ) than when they paid by cash, although the proportion of day-to-day essentials such as bread, vegetables and fruit – the so-called "virtue products" - remained the same.
The reason, according to the scientists, is that paying with plastic somehow doesn’t feel “real”, so we tend to make less considered decisions about purchases than we would if we were handing over real money. Paying with cash is more “painful” and so helps to curb the impulse to chuck another giant bag of crisps into the trolley.
Apart from handing over hard cash, the study suggests two other shopping tips to aid weight loss. Firstly, people who shop at the weekend are less likely to make impulse purchases of “vice products”, perhaps because they are more likely to use a shopping list as a guide. Weekdays tend to be busier for most people, so there is a tendency to rush in and out of the store without thinking too much about healthy food choices. Secondly (unsurprisingly) those who use a smaller trolley/basket are less likely to purchase junk food than those who use large trolleys. The obvious reason for this is that if you use a smaller trolley, you only have room for the essentials. So the next time you head for the supermarket, you may want to stop at the nearest cash-point on the way.
A version of this article appeared in Reader’s Digest
Dr David Ashton
8th July 2011
