Â鶹ÒùÔº

Can small changes in the design of food delivery apps encourage people to choose more climate-friendly meals?

Researchers at the Institute for Food and Resource Economics (ILR) at the University of Bonn recently investigated this question. Their have now been published in the journal Appetite.

We are what we eat—and our eating habits affect not only our health but also the health of our planet. Food systems are among the main contributors to global greenhouse gas emissions and cause environmental problems such as deforestation and land use change. With the boom in online food delivery, the influence of digital platforms on our daily food choices is growing. This raises the question: How can food delivery apps be designed so that sustainable options become the easy and attractive choice?

Nudges and boosts: What are they?

In this study, two different approaches were tested to promote sustainable food choices in an experimental online app. The basis was a control group that used the app without these features. In the first intervention—"Default+ nudge"—a climate-friendly burger menu was preselected by default. Participants could accept this choice or create their own menu. If they opted to customize their meal, the more environmentally friendly products appeared at the top of the list and were highlighted with a green leaf icon.

The second intervention—"Information+ boost"—focused on education and motivation. Participants were shown four simple tips for sustainable eating. A banner reminded them that their choice makes a difference, and real-time feedback showed the estimated CO₂ emissions of their menu. In all conditions, including the control group, users could click to see additional information on the estimated carbon footprint and the nutritional table for each menu item.

Three experimental groups

Participants were randomly assigned to one of three experimental groups. In this online study, participants used a food delivery app modeled after a real one, and put together a burger meal, consisting of a bun, patty, toppings, sauce, side dish, and drink. A total of 1,011 people completed the initial survey and were invited to a follow-up survey a week later, with 664 taking part. This time, they again assembled a burger menu—but without the interventions described above. Neither the "Default + Nudge" nor the "Information + Boost" measures were used in the second round.

With the "Default+ nudge" approach, participants chose meals with an average CO₂ footprint of 1,530 grams—about one-third less than the control group (2,280 grams). The "Information+ boost" approach, which provided tips and feedback, only slightly reduced the footprint to an average of 2,169 grams. However, neither approach led to lasting change—after one week, all groups made similar choices to the control group in the first round.

Change takes time

The findings show that one-off interventions are not enough to sustainably change consumer behavior. However, this does not mean that change is impossible. Other studies in different contexts show that repeated exposure to interventions, combining nudges and boosts, or incorporating emotional elements can have stronger and sometimes lasting effects.

The biggest challenge was identifying measures that—based on theory and empirical studies—have the potential to positively influence consumer behavior, can be clearly classified as a "nudge" or "boost," and—crucially—be perceived as realistic in the context of a food delivery app.

Results could be transferrable to other cases

In principle, the results could be transferrable to other cases, but with caution. The study was conducted in a simulated delivery app—participants neither paid nor received burgers, so there was no real purchase. Nevertheless, the results suggest that nudges can be an effective tool to influence decisions in the short term. Boosts, however, may need to be repeated or combined with other approaches to achieve stronger and longer-lasting effects.

Food delivery platforms could move toward offering climate-friendly meals as the default option and use additional nudges to help make the sustainable choice the obvious one. Given growing sustainability challenges, closer cooperation between food companies and researchers would also be desirable. This would allow the development and testing of measures in real-world application that promote long-term behavioral change.