Eco-friendly dining: food app layout cuts meal carbon footprint

App-based and online food delivery services such as Just Eat in the UK and DoorDash in the US are increasingly popular, so how can policymakers influence consumer decisions to reduce the carbon footprint of food choices made on these platforms? 

Such policy interventions are vitally important given that greenhouse gas emissions from the food system, including production, transport and packaging, constitute about one-third of the global total. Meat production is far more carbon-emitting than other farming given methane gas from cattle, fertiliser used in animal-feed crop production, and much greater land use in farming livestock compared to other farming.

Cambridge study reveals menu design on food apps can cut meal carbon footprint by 12% 

Research led by Cambridge Judge Business School finds that adjusting the order of food on delivery-app menus – so the lowest carbon-impact dishes and restaurants are presented first – significantly reduces the average meal carbon footprint, while a meal tax (which adjusts meal prices based on the carbon content of their meat ingredients) and carbon-footprint label (providing information) has little such effect.  

Such menu positioning, known as ‘choice-architecture intervention’, reduced the average meal order carbon footprint by 12% per order, driven by a 13% reduction in high-carbon main meal choices. 

“We show that menu repositioning offers an effective and highly accepted yet minimally intrusive strategy to support a shift towards more sustainable and healthy diets,” says the research based on 4,008 participants in the UK using an interactive system that mimics popular food-delivery platforms such as Just Eat, Deliveroo, DoorDash, Grubhub and Uber Eats. 

Promoting sustainability via menu choices 

“For policymakers and decision makers on all levels (including schools and canteens), moving the more sustainable choice to the top of a menu would be a feasible, impactful, and cost-effective policy intervention.” 

The research is co-authored by Paul Lohmann, Research Associate at the El-Erian Institute of Behavioural Economics and Policy at Cambridge Judge Business School, and Lucia Reisch, El-Erian Professor of Behavioural Economics and Policy at Cambridge Judge and Director of the El-Erian Centre. 

Previous research in this area has mostly focused on interventions in grocery retail and cafeteria settings. The recent growth of food-delivery apps and websites therefore offer “an unparalleled opportunity to promote sustainability,” says co-author Paul Lohmann. “These food-delivery platforms integrate menu design, price changes and emissions information at the point of purchase for consumers.”

Food app menu design boosts nutrition, satisfaction, and corporate responsibility 

Beyond promoting a lower carbon footprint, the research found that menu repositioning has significant health and well-being benefits because the average meal order has “greater nutritional value and fewer calories, whilst significantly increasing self-reported satisfaction with the meal choice.” 

From a practical business perspective, the research says that online food platforms can use choice architecture as a cost-effective approach to demonstrate corporate responsibility toward health and climate change issues. 

Study surveys UK food app consumers to establish carbon footprint reduction 

The 4,008 adult UK consumers recruited for the research were asked to complete a food-choice task on a platform resembling popular delivery apps.  

The platform included 9 real-world-representative restaurants (with names such as Tommy’s Burger Place, Alfredo’s Pasta and Millie’s Salad Bar), offering a variety of popular cuisines (including Italian, Chinese and Japanese) and dishes ranging from the low-carbon impact (Mixed Grains Salad, Houmous and Falafel Salad and Vegetable Korma with Rice) to high-carbon impact (Double Cheese Burger, Beef Lasagna and BBQ Beef Pizza).  

Each restaurant’s menu included various starters, mains and desserts, so participants could select from 164 unique food items for which the researchers calculated the carbon footprint and calorie content. 

Only active food-app consumers who live in urban areas were eligible to participate, and the participants were 52% female with an average age of 38 and average annual income of £35,000. About 6% of participants said they were vegetarian and 2% said they were vegan, percentages that align closely with recent UK dietary surveys. 

About 77% of participants used a mobile device or tablet to place their order, with 23% using a personal computer. The average energy content of the chosen food items was 1,069 Kcal. 

After placing their order, participants then completed a survey that measured satisfaction with their food choice, factors influencing their decision, and support for a range of policies that could be implemented on online-delivery platforms. 

In detail, the results showed that the carbon footprint was about 12% lower in the menu repositioning condition (2.24 kg CO₂e/serving) compared to the study’s control (2.55 kg CO₂e/serving), whereas emissions were only marginally lower than control in the meat-tax (2.47 kg CO₂e) and carbon-labelling conditions (2.54 kg CO₂e). 

Who is most influenced by choice architecture? 

The study also looked at the influence of choice architecture among different demographic groups. While there was no significant difference between age groups, male participants were more affected by the repositioning intervention than women. The study found that repositioning is effective in reducing the carbon footprint of food choices regardless of participants’ social and economic status, “with both high- and low-income/education participants responding similarly to the nudge”. 

People who use food apps vary in their approach, with some taking plenty of time to choose carefully while others rapidly order a pizza during a quick break in sporting action on television. So how does this affect response to menu repositioning? 

Meal timing and decision speed key to menu design effectiveness 

The research distinguished between the very quick decisionmakers (those who made their choice in less than 60 seconds, with a median of 41 seconds) and those who took more than a minute (median of 126 seconds) to choose their meal. The research also examined food self-control and the timing of participants’ involvement in the study – specifically whether it occurred around lunchtime or dinnertime (when participants may be more hungry), or at other times of the day. 

“We find that individuals who spent less time on the task (<60 seconds), held high levels of food self-control, or completed the survey near a mealtime (lunch or dinner) were particularly affected by the choice-architecture intervention,” the study says. 

The authors had hypothesised that people with high food self-control would be less responsive to choice architecture. They suggested that the fact that they were actually more responsive may reflect that the repositioned menu made it “easier for them to act on their pre-existing intentions without additional deliberation”.

Labelling and meat taxation only effective on knowledgeable consumers

Carbon literacy – baseline knowledge about the carbon impact of food – was also explored. For participants with higher carbon literacy, both the meat tax and labelling significantly reduced the greenhouse gas emissions of their food choices, while for people with low carbon literacy “labels likely require more time and repetition to translate into knowledge gains, and ultimately to affect habit formation”.

The authors thus conclude: “Notably, we find that labelling and meat taxation are effective only in encouraging lower-carbon food choices for people with more a priori knowledge of the climate impact of food consumption”, but that nudging works best for the average consumer.