Climate-friendly diets in your pocket: New app uses behavioural science principles to change eating habits

Many people want to eat more sustainably, but good intentions often fall short when it comes to long-term behaviour change.

With the MAINTAIN project, researchers at the University of Southern Denmark (SDU) aim to bridge that gap by developing a digital intervention that applies behavioural science (e.g., habit formation) and gamification principles to promote lasting changes in dietary habits.

- We know that people want to eat in more climate-friendly ways, but it takes more than motivation. It also requires knowledge, support, and the right tools for habit formation in everyday life. This project allows us to explore how digital technology and playful elements can make sustainable choices more viable and enjoyable, says Professor Nikos Ntoumanis, who leads the project from SDU’s Danish Centre for Motivation and Behaviour Science (DRIVEN) at the Department of Sports Science and Clinical Biomechanics.

The project brings together a broad interdisciplinary team across SDU - including DRIVEN, FOOD MATTERS, Life Cycle Engineering, and Citizen Science - alongside international collaborators from France, Spain and the USA.

A playful approach to serious challenges

At the centre of the project is a mobile app that uses game-based features such as points, challenges and visual progress tracking to motivate users to make climate-friendly food choices.

The goal is to make sustainable eating feel less like a restriction - and more like an engaging journey. Other principles of behavioural science will also be utilized, such as habit formation and planning.

But the app is not being developed behind closed doors. From the start, citizens, consumers and relevant stakeholders will be actively involved in co-designing the solution through workshops and feedback sessions, facilitated by SDU’s Centre for Citizen Science.

From idea to impact

To test the real-world effect of the app, the research team will conduct a randomized controlled trial.

One group of participants will receive access to the new digital tool, while a control group will not. By comparing changes in food choices across the two groups, the researchers can evaluate the intervention’s effectiveness in promoting lasting changes in sustainable food choices.

- By combining citizens’ perspectives with behavioural science and climate research, we hope to develop a solution that not only supports short-term changes, but creates lasting impact, says Nikos Ntoumanis.

Understanding what works - and why

Beyond simply measuring outcomes, the project seeks to understand the psychological and social drivers behind dietary change.

Researchers will combine data from the app with surveys, interviews and qualitative feedback to explore users’ motivation, taste preferences and contextual factors.

A life cycle assessment will also be conducted to estimate the potential CO₂ savings if the recommended diet is adopted at scale.

Long-term vision: Scalable, citizen-driven sustainability

The ambition is that the digital solution will not only benefit individual users but also be applicable in broader health promotion and climate action - for example in municipalities, public health initiatives or in collaboration with food industry stakeholders.