Background Food retailing is undergoing a fundamental transformation. Digital on-demand technology is dramatically reshaping food distribution and delivery, making food and prepared meals more accessible and convenient. The impact of this disruption on food purchasing and consumption behaviour and dietary inequalities is unknown. This study aims to explore whether there is a social gradient in use of digital food delivery services for both take-away food and grocery purchasing, and whether use of these services is associated with BMI.

Methods We used data from UK Kantar Fast Moving Consumer Goods (FMCG) panel, a nationally representative panel study of all take-home household food and beverage purchasing. We used data from London and the North West of England (n=1559) from February 2019. Households reported usage of digital take-away food delivery services (past 7 days) through a bespoke online survey. We used logistic regression models to estimate the odds of delivery service usage by occupational grade (AB, C1, C2, DE) and income (£0–20K, £20+-50K, £50K+) and to estimate whether usage was associated with BMI category (<25; 25–29; >30), derived from self-reported height and weight. Results were adjusted for potential socio-demographic confounders.

Results For take-away food purchasing, 13% of survey respondents had used a digital delivery service in the past 7 days. In fully adjusted models, a dose-response pattern was observed with lower occupational grade associated with higher usage for both C2 (OR 1.66, 95% CI 1.01,2.73) and DE (OR 1.92, 95% CI 1.18,3.09) households, compared to AB. Similar patterns were observed for household income. Use was associated with BMI category 25–29 (OR 1.52, 95% CI 1.10, 2.29) and 30+ (OR 1.8, 95% CI 1.18, 2.72), compared to <25. For digital grocery purchasing, 15.6% of households had used a delivery service in the past month. In fully adjusted models, there was no association by occupational grade. For household income, the highest group (£50K+) had highest odds of use (OR 1.79, 95% CI 1.12, 2.84), compared to £0–20K. There was no association with BMI category.

Conclusion There is a social gradient in use of digital take-away food delivery services, with greater use in more socio-economically disadvantaged households. Use is positively associated with BMI. For digital grocery delivery there is no clear pattern, though there is some evidence that use is highest in high income households. This suggests socio-economic inequalities in diet and obesity have the potential to be exacerbated by adoption of digital food technology.