Association between climate concern and weight status: mediation by dietary patterns

Background

To our knowledge, no studies have yet examined the association between climate concern and weight status. A more plant-based dietary pattern is known to benefit both health and climate, individuals with higher climate concern are more likely to adopt such patterns. Therefore, this study investigates this association and the potential mediating role of dietary patterns within a ‘One health, one planet’ framework.

Methods

Data were drawn from the Belgian Health Interview Survey 2023-2024, a cross-sectional household survey. The independent variable climate concern (“How important is the issue of climate change to you personally?”: extremely to very vs. somewhat to not at all) was assessed via a self-administered questionnaire. The dependent variable weight status was defined as non-overweight vs. overweight (BMI ≥ 25, based on self-reported weight and height) and the mediator dietary pattern (“Allocate your diet to a nutritional pattern?”: omnivore vs. more plant based (from flexitarian to vegan)) were reported via a face-to-face interview. Mediation analysis was performed using SAS CAUSALMED, adjusted for sex, age, education, daily consumption of soft drink and snacks, and physical activity, among adults (≥ 18 years; n = 4672).

Results

Climate concern was associated with weight status (total effect: OR = 1.24, p = 0.0020). Mediation analysis indicated that this association was partially explained by dietary pattern, with a direct effect of OR = 1.20 (p = 0.0084) and an indirect effect, i.e. the effect that is mediated by dietary pattern, of OR = 1.04 (p<.0001), accounting for 17.4% of the total effect.

Conclusions

Adults concerned about climate have a lower likelihood of overweight, partly explained by greater adherence to more plant-based dietary patterns. These findings suggest that promoting plant-based diets may contribute to overweight prevention and offer co-benefits for climate policy.

Key messages

• Climate concern is associated with a lower likelihood of overweight, partly mediated via more plant-based diets.

• More plant-based diets benefit both overweight prevention and climate action.