Digital marketing techniques within online food retail platforms: a scoping review.

BACKGROUND: There is growing evidence that online food retail platforms (online food delivery, online grocery and meal kits) use a range of marketing techniques to promote unhealthy foods (energy-dense and nutrient-poor) to influence consumers' food choices and food purchases. However, existing literature on this topic is dispersed (across public health and marketing disciplines) and has not been synthesised from a public health perspective. The aim of this review was to synthesise the evidence on the digital marketing techniques prevalent on online food retail platforms, what food products they promote and their potential influence on consumers' online food purchase behaviours. METHODS: A mix of health and business databases was searched for peer-reviewed papers published in the last ten years, to align with the time from when online food retail platforms grew in popularity. Included studies were mapped to a pre-defined list of digital marketing techniques, marketing mix strategies and across Cialdini's principles of persuasion. All findings were described narratively. RESULTS: A total of 3408 studies were screened, of which 16 studies were included in the review. Eleven studies examined online food delivery services, and five studies examined online grocery retail services. A range of well-established digital marketing techniques were identified, including algorithmic personalisation, push notifications, membership-based models, interactive tools such as sorting and filtering features, hyperlinks or prompts to create combo deals, site customisation offering personalised shopping experience, clickable banner advertisements and search engine optimisation. Whilst these are standard techniques in digital commerce, we found that they were often deployed to preferentially promote nutrient-poor foods. Specifically, seven studies highlighted the use of these marketing techniques to promote foods of poor nutritional quality, with marketing strategies reinforcing perceptions of value, tastiness and pleasure. Only two studies examined and reported a positive influence of using price promotion techniques on consumers' unhealthy food purchase intention. CONCLUSIONS: Online food delivery and online grocery platforms use a range of digital marketing techniques to deliver content in highly persuasive ways, often promoting unhealthy food options. Future research should explore how these platforms can be leveraged to enable healthier population food choices and align with public health objectives.