Researchers from Belgium's Hasselt University report in the scientific journal npj Climate Action found that those taking part in the challenge ate on average a quarter less meat than the control group in the study. It was the involvement of their friends or family that ensured they maintained this reduction three months later.
The study followed 1,213 Dutch and Flemish participants for four months and asked them to complete a questionnaire about their eating habits four times. The participants were randomly assigned to three groups:
- Group one: The 'individual group' was asked to participate in the Veggie Challenge, a coaching programme for eating more plant-based and fewer animal-based foods, supported through a special mobile app.
- Group two: The 'social group' was not only asked to follow the programme, but also encouraged to invite their friends or family to participate or involve them in the challenge. The app offered the opportunity to do this through a 'Veggie Challenge team'.
- Group three: A third group served as a control group and only completed the questionnaires which were also given to the other groups.
A 'randomised study' is considered the ‘gold standard’ in science for determining the effectiveness of actions aimed at behavioural change.
After the 30 days, the average consumption of animal products (meat, fish, dairy and eggs) in both the individual and the social group was 16-17% lower than in the control group, a statistically significant difference. Meat consumption was 22%-27% lower. At that time, no significant differences were visible between the individual and social groups.
A month later, things were very different. The average consumption of the individual group bounced back, almost to the same level as that of the control group. But the reduction was maintained in the social group. Even at a third measurement, after three months, meat consumption in the social group remained stably reduced by 25% compared to the control group.
Lead researcher Rosaly Severijns said: “Research into measures for behavioural change often shows that it is difficult to permanently change behaviour.
“This research shows that encouragement received by involving friends and family provides the social support needed to eat fewer animal products over the long term. Such a simple encouragement could also be used more widely to encourage other environmentally friendly or healthy habits.”