Conducting industry informant interviews to advance healthy food retail initiatives: challenges, opportunities, and lessons.

Retail food environments influence dietary health, yet efforts to improve them have had limited success. Recruiting informants from the food and beverage retail industry for insider information has been challenging due to the sensitivity of inquiries and proprietary protections. Moreover, which recruitment approaches are successful are seldom disseminated. This paper aimed to bridge this gap by detailing the complexities of recruiting and interviewing four food industry insider groups-independent store owners, corporate chain managers, food and beverage distributors, and sales representatives of major companies-to provide insights and specific guidance for future research. From October 2021 to November 2022, we interviewed 49 industry informants to explore business and commercial practices used in the US food retail sector. Recruitment methods were tailored to each group, and qualitative data were collected through in-person or virtual 'walk-along' interviews with customized interview guides. Across the study, we experienced distinct challenges around participant inaccessibility, hierarchy within corporate chains, skepticism, mistrust and variation in knowledge across industry groups. We detail our response to these challenges through four lessons learned, including persistence and flexibility, the importance of vetting, the value of trust-building measures and adapting the study protocol to new information. Given our success in reaching industry groups and accessing insider information, we provide key recommendations that future researchers can use to engage diverse industry groups and advance efforts to promote healthy food retail.