Together, not alone: The secret behind a sustained sustainable diet

*Disclaimer: Please note that parts of this English sci-fly were automatically translated.*

If you read the title, you might think that today I am going to talk about a popular Dutch song by Little John and DJ DYLVN. That is not the case, but feel free to turn on the song and enjoy a nice Dutch tune while reading this blog. What I do want to talk about today: A sustainable diet, especially how to keep it up.

An eating pattern consisting of less animal protein (found in meat, fish, dairy and eggs, among other things) and more vegetable products (such as vegetables and legumes) is sustainable because it is good for your own health as well as for the planet we live on. Although more and more people recognize the importance of a more sustainable diet, it can be quite difficult to apply a more sustainable diet in your own life and actually maintain it for a longer period of time. A recent study therefore investigated whether it works to encourage people to eat less animal products and more vegetable products through an app-based challenge. It also investigated whether it helps to involve family and friends in the challenge.

Background

• A challenge to eat less animal products and more plant-based via an app appears to be effective in starting a more sustainable diet;
• 1 month and 3 months after the challenge, the effect seems to be visible only for a group of participants who involved their friends and family in the challenge.
• So making your diet more sustainable seems to be more sustainable in the long run if you involve your own friends and family. After all, did Little John and DJ DYLVN have an important lesson to share with their song: “Samen, niet alleen!” (“Together, not alone!”).

Research Method

WHAT?
The research questions were, “Is participating in the ”Veggie Challenge“ effective in reducing eating animal products?” and “Is involving family and friends in this ”Veggie Challenge“ important?”.

WHO?
1213 adults from the Netherlands and Flanders participated in this study. Participants were mostly women and highly educated, and their average age was 47. The participants were divided into three groups for the study:

• a control group of 243 participants who only completed the questionnaires for this study;
• a group of 485 participants who followed the Veggie Challenge individually through the app;
• a group of 485 participants who followed the Veggie Challenge through the app and could involve their friends and family. They could create a team in the app with their friends and family, create a WhatsApp group, view the progress of team members, and get feedback on the sustainable diet at the group level.

HOW?
To answer the research questions, the study looked at whether the three groups started eating less animal products. Participants (excluding the control group) were challenged for 30 days via the “Veggie Challenge” app to eat less animal products. The app included sharing recipes and providing feedback on the participant’s sustainable behavior (e.g., reduction in greenhouse gas emissions achieved). Participants’ consumption of animal products was measured prior to, immediately after, 1 month after, and 3 months after the Veggie Challenge.

Results

• Participation in the Veggie Challenge resulted in a 16-17% decrease in eating animal products immediately after participating in the challenge. This was accompanied by a 21-24% reduction in greenhouse gas emissions.
• This effect remained visible until 1 and 3 months after the challenge, but only for the group that had involved their family and friends.
• The decrease in eating animal products was not visible for the control group.
• Eating meat decreased the most, compared to eating fish, dairy and eggs. Also, the decrease in eating animal products was most evident in people who ate more meat prior to the challenge.

Reference

Severijns, R., Asanov, I., Streukens, S., Bruns, S. B., Moleman, P., Brouwer, J., van Griethuijsen, J, & Lizin, S. (2024). Involving family and friends helps sustainable diets last longer. npj Climate Action, 3(1), 109. https://doi.org/10.1038/s44168-024-00192-4

This sci-fly was written by Dr. Nina van den Broek (Behavioural Science Institute, Radboud University), for RAD-blog, the blog on smoking, alcohol, drugs and diet.Background search with teaching in the Bachelor’s and Master’s programmes in Educational Sciences, and she will continue to work as a lecturer in these programmes after completing her PhD.