Fancy a bar of chocolate? Wait 25 seconds and craving will go
Pausing for just 25 seconds before buying a chocolate bar can be enough to see off the craving in favour of a more healthy snack, new research suggests.
A trial using vending machines in the US found that having to wait for sugary treats made them less desirable.
Scientists installed countdown timers on the machines, forcing customers who had ordered chocolate or other unhealthy products to wait 25 seconds before the items became available.
They were able to change their mind and select a healthy snack at any point during the countdown, which would then become instantly available, while those who selected something healthy in the first instance were not forced to wait at all.
Over 14 months, the team found the delay prompted up to a 5pc increase in the purchase of healthy snacks, but that the new software did nothing to harm the revenues brought in by the machines.
Obesity campaigners have welcomed the study and said there will be "no excuse" not to install the technology on all modern vending machines.
Previous interventions to try to reduce the harm caused by the easy availability of sugary snacks have focused on the complete removal of such products, or the machines altogether.
But many organisations, including leisure centres and businesses, are reluctant to get rid of their vending machines because they rely on the profits that they generate.
"Having to wait for something makes it less desirable," Dr Brad Appelhans, who led the research at the Rush University Medical Centre in Chicago, said.
The research team also found that offering a 25pc discount on healthy snacks or imposing a 25pc tax on less healthy snacks influenced buying patterns.