Association between the socio-economic status of households and a more sustainable diet.

OBJECTIVE: A sustainable diet is an affordable diet with low environmental impact, high food security and sufficient healthiness. The present study aimed to assess the correlation between the socio-economic status of households and a sustainable diet. DESIGN: The food basket and socio-economic data of Iranian households were evaluated during 2016-2018. The households were classified based on the sustainability of their diet by determining the dietary carbon footprint, dietary water footprint, lower dietary costs of the household than the median and a higher dietary quality index than the median. Logistic regression was used with four models to calculate the OR of a more sustainable diet as the dependent variable regarding the different quartiles of socio-economic status (SES) as the independent variable. SETTING: Iran. PARTICIPANTS: Iranian households (n 102 303), nationally representative, were studied. RESULTS: Lower SES was associated with the higher OR of a sustainable diet (OR: 0·90; (95 % CI 0·87, 0·91)). Higher quartiles of SES compared with the lower SES group indicated the higher energy intake and consumption of more dairies, meat, poultry, fish, eggs, legumes, nuts and fruits, as well as the lower intake of bread, cereal, rice and pasta. CONCLUSION: In countries such as Iran, where nutrition transition occurs rapidly, better economic and social levels in the populations with a higher SES are associated with increased energy intake and higher consumption of animal-based foods, which decreases sustainable diets compared with the groups with a lower SES.