Vending machines with healthy snacks and drinks may lure more people to buy these products with signs promoting their benefits than with price cuts for more nutritious selections, a study suggests.
For the study, researchers experimented with 28 food and beverage machines on a university campus for five months. They tested out three options alone or in different combinations: restocking machines with healthy options; discounts for nutritious choices; and signs touting advantages like less sugar or fewer calories.
Just cutting the price of healthier items by 25 percent didn't sway consumers. Both unit sales and revenue fell compared to the same five-month period in the previous year.
“We were surprised that reduced cost was not a driver for people to select the healthier snacks and beverages,” said senior study author Jeannette Ickovics, a public health researcher at Yale University in New Haven, Connecticut.
Researchers had expected each of the three options to independently inspire healthier food and beverage selections, Ickovics and colleagues note in the Journal of the Academy of Nutrition and Dietetics, online February 4.
They also hypothesized that the combination of all three interventions - restocking, discounts and signs - would have the greatest influence on consumers.
What they found instead was that the picture looked different for snacks than for beverages, and that restocking and promotional signs helped more than price.
In snack machines, adding healthier items and discounting these products was associated with sales of 460 more units during the study period than the same period a year earlier. This combination also resulted in increased revenue of $1,039.
In beverage machines that discounted healthy choices in addition to doing these two other things, sales only increased by 66 units over the previous year
With beverage machines, restocking with healthier options and posting signs was associated with increased sales of 204 units. In beverage machines that discounted healthy choices in addition to doing these two other things, sales only increased by 66 units over the previous year.
Before the experiment, the best-selling snacks were Twix, Snickers, MandM Peanuts, Doritos Nacho Cheese and Planters Nuts and Chocolate Trail Mix - none meet the “FitPick” nutrition standards laid out by the National Automatic Merchandising Association. These standards, for example, require snacks to be no more than 250 calories with no more than 20 grams of sugar and 10 grams of fat.
During the study, all of the top sellers met these nutrition standards: Whole Grain Pop-Tarts Cinnamon, Sun Chips, Doritos Reduced Fat Nacho Cheese, Snyder’s Honey Mustard Pretzels and Lay’s Oven Baked Barbecue Flavored Potato Crisps.
All the top-selling beverages before the experiment were sodas: Diet Coke, Coke and Coke Zero. During the study, these remained best sellers but Dasani water also made the list.
“Sometimes all we need is a little ‘nudge’ with some promotional signs reminding us to make the healthier choice - products lower in sugar, salt and fat,” Ickovics said by email.
Limitations of the study include its small size and the possibility that at least some of the shifts in vending machine purchases might be due to the novelty of new items and not a sustained effort by consumers to buy healthier things, the authors note.
Previous research has shown price manipulations can impact people’s food choices, including what they buy from vending machines, noted Myles Faith, an education researcher at the University of Buffalo in New York.
In the current study, it’s possible signs provided an “environmental nudge” to buy better things than merely stocking healthy snacks could accomplish on its own, Faith, who wasn’t involved in the study, said by email.
“People often approach vending machines in a rush and pressed to make a selection without much thinking, almost in autopilot,” Faith added. “However, as this study shows, there can be a range of healthier selections in some vending machines if one slows down to look carefully.”
Signs can help with that.