If we knew the carbon footprint of our favorite restaurant meal, would we choose a different dinner? This is what Ann-Katrin Betz and colleagues at Julius-Maximilians-Universität Würzburg set out to investigate in a recent study. The researchers gave would-be diners menus that specified each meal’s carbon footprint, or menus that gave high-, medium-, and low-emission options, and then asked them to choose their dinner.
Previous research has shown that people’s food choices substantially affect their personal carbon footprint. However, most studies examining factors that influence environmentally relevant food choices have focused on grocery purchases.
In the current study, Betz and colleagues used an online survey of 256 volunteers to explore how restaurant menu design might influence diners’ awareness of the climate-related impacts of their dinner choices. They created nine hypothetical menus in order to test two different design approaches: dishes described along with each one’s carbon label indicating the amount of greenhouse gas emissions associated with its production, and dishes given with options that were high-, medium- or low-emission alternatives.
One example of a modifiable dish was a couscous salad that could be ordered with beef (high emission), shawarma (poultry; medium emission), or falafel (low emission). On six of the menus, the main dishes were presented with different default options – the side dish was associated either with the highest, or with the lowest greenhouse gas emissions.
The researchers asked each volunteer to choose exactly one meal that they would order from each of the nine different menus. This appears to be the first published study to simultaneously explore the effects of default options and carbon labels on food choice.
After statistical analysis, the findings showed that participants selected more climate-friendly dishes when carbon emission labels were present, as well as when defaults consisted of low- rather than high-emission options. These findings are in line with results from earlier studies that explored the two approaches separately.
The results of the study, published today in the journal PLOS Climate, suggest that the design of restaurant menus has a considerable effect on the carbon footprint of dining out. Restaurant owners could use carbon labels for each dish, and could also use the most climate-friendly component as the default option in modifiable dishes with variable components, as both these options could reduce the carbon footprint of their business.
The researchers emphasize that more research is needed to inform such strategies, including investigations into interactions between the two approaches, the impact of personal habits – such as vegetarianism – on menu choices, and menu choices in real-world settings.
“If we want more climate-friendly restaurant visits, highlighting dish components on a menu can really be an important parameter because it communicates what is normal and recommended,” said the study authors. “It may also be one of the easiest things restaurant owners can do.”