{
  "abstract": "Background There is a need to understand how to implement food system interventions that promote healthy and sustainable diets for all populations. Online grocery retail is increasingly popular and many interventions which aim to promote healthier and more sustainable foods in-store may also be viable in online retail settings. This study was a process evaluation of a plug-in based, online grocery intervention which involved: i) eco-labelling of food products, ii) product swap suggestions to more sustainable alternatives with price discounts on suggested swaps. We explored intervention implementation, how and why it worked, for whom, and in what circumstances.Methods A convenience sample of intervention recipients (n=24) and implementers (n=4) were recruited through an online survey panel to participate in semi-structured interviews. Interview questions explored determinants of online food purchasing decisions, the impact of the intervention on food choices, and perspectives on intervention mechanisms, and were grounded in realist principles. Data were thematically analysed.Results Recipients described that their engagement with the plug-in could be limited by their understanding of the intervention and level of exposure to it, their own health and sustainability literacy, and the extent to which they prioritised sustainability over product affordability, quality and comparability. They felt that intervention effectiveness would vary depending on recipient characteristics and shopping habits. Implementers described challenges relating to the development and implementation of the plug-in, including the technical knowledge required for development, and difficulties interacting with fluctuating supermarket websites. Facilitators of implementation included having available financial and technical resources, such as pre-existing plug-in components.Both implementers and recipients felt that the intervention acted through nudge principles and increasing recipient knowledge, though recipients also described a sense of guilt about choosing less sustainable products which might encourage changes to shopping behaviours. Recipients described opportunities for intervention optimisation, such as increasing usability amongst different shoppers, including those who predominantly shop in-store, and the use of concurrent marketing strategies to promote uptake. Implementers felt that ultimately, sustainable changes to online food systems will be brought about by policy action rather than smaller-scale interventions.Conclusion Consumers found interventions to promote more sustainable alternatives when online grocery shopping to be acceptable and potentially effective, though recipients and implementers highlighted opportunities for optimisation and scalability. Understanding the mechanisms behind intervention impacts, barriers to implementation, and strategies for optimisation, is important for future food system interventions and policies.",
  "authors": [
    {
      "affiliations": [
        "Department of Public Health, Environments and Society, London School of Hygeiene and Tropical Medicine, London, UK"
      ],
      "name": "Oliver Huse"
    },
    {
      "affiliations": [
        "Department of Public Health, Environments and Society, London School of Hygeiene and Tropical Medicine, London, UK"
      ],
      "name": "Suzan Hassan"
    },
    {
      "affiliations": [
        "Department of Public Health, Environments and Society, London School of Hygeiene and Tropical Medicine, London, UK"
      ],
      "name": "Bea Savory"
    },
    {
      "affiliations": [
        "Department of Public Health, Environments and Society, London School of Hygeiene and Tropical Medicine, London, UK"
      ],
      "name": "Greg Hartwell"
    },
    {
      "affiliations": [
        "Centre for Research in Public Health and Community Care, University of Hertfordshire, Hertfordshire, UK"
      ],
      "name": "Claire Thompson"
    },
    {
      "affiliations": [
        "Department of Public Health, Environments and Society, London School of Hygeiene and Tropical Medicine, London, UK"
      ],
      "name": "Laura Cornelsen"
    },
    {
      "affiliations": [
        "Department of Economics, University of Warwick, Coventry, UK"
      ],
      "name": "Thijs van Rens"
    },
    {
      "affiliations": [
        "Department of Economics, University of Warwick, Coventry, UK"
      ],
      "name": "Oyinlola Oyebode"
    },
    {
      "affiliations": [
        "Department of Economics, University of Warwick, Coventry, UK"
      ],
      "name": "Helena Bentil"
    },
    {
      "affiliations": [
        "Department of Public Health, Environments and Society, London School of Hygeiene and Tropical Medicine, London, UK"
      ],
      "name": "Steven Cummins"
    }
  ],
  "title": "P78 The implementation of an intervention to promote sustainable and healthier food choices in online supermarkets: a qualitative process evaluation",
  "uid": "c5f2f4f6-5269-5eab-bef6-4cefd3036576"
}