Moving Coke Zero into the first spot on a McDonald's touchscreen menu significantly increased its sales.

By Mike Pomranz
Updated July 23, 2019

When ordering a meal, the menu itself may play a bigger role than you realize. Subtle things like the order in which items are listed or how they are highlighted can subconsciously nudge diners towards purchasing certain foods. Earlier this year, a study showed that even something as silly as using a handwritten font can make a menu item seem healthier. Now, a new study suggests that the way items are listed on a menu may help people make actual healthier decisions, too.

For the study, published in Psychology & Marketing, a team of British researchers looked at two things that generally aren’t considered very healthy: soda and McDonald’s. They wanted to see if a small change could affect customers’ behavior in a positive way, so they made a tiny tweak to the menu screens at 622 McDonald’s locations across the England and Wales: Of the six soda choices listed on the touchscreen, Coke Zero was moved from third to first, and regular Coca-Cola was moved from first to last. As expected, comparing sales during the 12 weeks before and after this change, though Coca-Cola remained the most popular choice, its sales dropped significantly while sales of Coke Zero increased by about the same amount. Specifically, the median store’s sales of regular Coke dropped from 4,558 to 4,213 while sales of Coke Zero increased from 1,043 to 1,360. Overall, soda sales remained about the same. (And for the record, sales of Diet Coke and Fanta also inched up a bit.)

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“The present study demonstrates that a light‐touch, low‐cost nudge can decrease how often a sugary soft drink is purchased and increase how often a no sugar soft drink is purchased,” the authors conclude. The paper explains this phenomenon by saying that McDonald’s customers tend to look at the first listed drink first, and “many who found the first item they looked at satisficing” chose it without considering other options. “Put another way, our theory is that if consumers’ act as satisficers (rather than as maximizers) when choosing soft drinks and find Coke Zero to be a satisfactory option, then presenting Coke Zero in the first place they are likely to look will cause many to choose this more healthful option (or at least consider options other than Coca‐Cola),” study states. “It is possible that some consumers mistakenly selected Coke Zero thinking it was Coca‐Cola, but these initial mistakes alone cannot reasonably explain the results of our longer‐term analyses.”

Later, the authors present these findings as broad advice. “In closing, we encourage managers and public policymakers to consider how the physical layout of their environment influences people’s expectations and to think about how those expectations can be leveraged to improve public health. Where habits have some command over human behavior, there is likely room for a nudge. This said, it is implausible that nudge interventions alone can solve overconsumption problems. Rather, nudges should be considered as just one part of a multifaceted approach to helping consumers make more healthful choices.”