Vending machine time delays promote healthier food choices

Delaying access to tempting, high-calorie foods and snacks in vending machines can potentially shift people’s choices to purchase less desired but healthier snack options.

Preventative medicine experts at Rush University Medical Center in Chicago investigated whether the human preference for immediate gratification could be harnessed to improve people’s vending machine snack choices.

There are 1.3 million snack vending machines across the US, making them the country’s most prevalent source of high-calorie snacks.

The researchers developed a new vending machine system and created a technology called the DISC system (Delays to Improve Snack Choices). The DISC vending machine system employs a ‘delay’ bar that separates the healthier snacks from the less nutritious options.

When an individual selects a less nutritious snack, the system begins a 25-second delay before the machine releases the snack from the vending machine.

The vending machine also has an LED screen, which displays the delay times for less healthy snack items, and a delivery countdown, which allows an individual to change their snack choice to a healthier option.

“This delay yielded a 2% to 5% increase in the proportion of total purchases from healthy snacks,” said Brad Appelhans, PhD, clinical psychologist at the Rush University Prevention Center and lead investigator on the study. “Also, we found that the delay did not harm total sales volume or vending revenue, which is important to vending machine operators.”

Prior vending machine interventions, which focused on complete removal of unhealthy snacks or the machines altogether, were found to be undesirable because they limit the options available and reduce the vending machine profits that schools, workplaces and other organisations count on.

The study, which covered a total of 32,662 vending machine snack sales, looked at six vending machine interventions employing a mix of time delay and pricing strategies.

“The beneficial effect on snack choice is about as large as that seen with discounts, but unlike discounts, time delays do not harm the total revenue of vending machines,” said Appelhans. “This could be a viable option for vending machine owners to offer good, healthy snack options while keeping their sales and avoiding out-of-pocket costs.

“Vending machines are conveniently located, have a broad reach and are the most prevalent source of high-calorie, nutrient-poor foods in the US,” said Appelhans. “They are not going anywhere any time soon, so this new vending machine system could be an effective and financially viable strategy that can shift individuals’ choices towards healthier options.”