Background Hot food prepared out-of-home is served ready-to-consume and is typically energy-dense and nutrient-poor. Using online food delivery services to purchase this food has become increasingly popular. These services increase access to food available out-of-home and possibly lead to more frequent consumption, which is associated with poor diet and living with obesity. Therefore, our study aimed to investigate the use of online food delivery services from the customer perspective to understand their reasons for choosing this purchasing format, including any advantages and drawbacks.

Methods We used a qualitative description approach to investigate our aims.

Between June and August 2020, we used Twitter and Reddit (social media platforms) to recruit ‘frequent’ online food delivery service customers (at least one order per month over the previous year) who lived in the UK, were aged 18–50 years, and able to communicate in English.

We used codebook thematic analysis to analyse data collected through semi-structured telephone interviews and NVivo (version 12) for data management.

Results The 22 participants in our study were aged 22–46 years, 12 were male, and 18 had completed further education.

Through codebook thematic analysis, we generated two primary themes. ‘Place. Time. Situation.’ with five sub-themes (‘The importance of takeaway food’, ‘Less effort more convenience’, ‘Saving money and reallocating time’, ‘Online food delivery service normalisation’, ‘Maintained home food practices’) and ‘Advantages outweigh recognised drawbacks’.

Participants acknowledged that by using online food delivery services they could purchase ‘takeaway food’, which was a food category that held sociocultural values, and maintain established and habitual practices. Participants cited access to a greater number of food outlets, streamlined purchasing processes, and promotional offers as reasons for favouring online food delivery services over other purchasing formats. Participants compared perceived advantages of using online food delivery services to drawbacks of increased unhealthy food consumption and business models that were seen as unfair to local outlets and delivery couriers. Participants believed the advantages outweighed the drawbacks, meaning they would continue to be frequent customers.

Conclusion Frequent online food delivery service customers reported that using this purchasing format facilitates habitual takeaway food consumption. Benefits not available through other purchasing formats meant that participants favoured online food delivery services in most situations. It is not yet clear if using online food delivery services increases overall consumption of energy-dense, nutrient-poor food. Future public health interventions that attempt to reduce the use of these services may help to improve dietary patterns.