Background: The current food system is responsible for significant environmental damage therefore, encouraging consumers to adopt an environmentally sustainable diet is a key public health challenge. Dietary guidelines have been developed that outline recommendations for purchasing and consuming food in an environmentally sustainable manner, but they have not yet been incorporated in UK national dietary guidelines.
Methods: Via an online survey of UK adults, we evaluated consumers' perceptions of the environmental benefit of various sustainable diet recommendations, their readiness to adopt these behaviours using the stage of change construct of the Transtheoretical Model, the factors that influenced their food choices, and their current consumption of plant- and animal-based sources of protein. Additionally, we investigated how demographic characteristics and food choice motives were associated with perceived environmental benefit of and readiness to adopt these sustainable diet recommendations.
Results: The survey was completed by 442 participants (66% female, 80% aged 25-54 years, 85% with higher education). The majority of participants considered the recommendations to 'reduce consumption of air-freighted foods' (79%), 'reduce food waste' (75%), and 'buy locally grown produce' (78%) to have a high environmental benefit, whereas a smaller proportion of participants perceived 'prioritise plant-based proteins' (42%) and 'choose organic produce' (27%) to have a high environmental benefit. Differences in perceptions and readiness to adopt sustainable dietary behaviours were observed between demographic groups, with women significantly more likely than men to be in action/maintenance (A/M) stages of change for prioritising plant proteins (OR 0.54), and younger participants more likely to be in pre-contemplation/contemplation (PC/C) stages of change for 'choose organic produce' (OR 2.03) and 'choose sustainable fish' (OR 2.45). Health, cost, environmental sustainability and taste were the most commonly reported food choice motives. Reporting environmental sustainability as a food choice motive was associated with readiness to adopt sustainable diet recommendations.
Conclusions: We found that consumers in the UK are engaged with some aspects of sustainable diets but remain resistant to others. The results of this study indicate that acceptable dietary guidelines could be developed to address environmental sustainability. Several behaviours were identified that consumers were willing to adopt, but there were barriers preventing them, highlighting that policy action is required to enable behaviour change to occur. Differences between demographic groups highlight potential targets for future campaigns promoting sustainable diets.
Keywords: Behaviour change; Dietary guidelines; Environment; Nutrition; Plant-based diets; Public health; Stage of change; Sustainable diets; Transtheoretical model.