PHASE 2 (Consumer Intercept Survey and Audit MAPP-S tool) A) Consumer Intercept Survey using questionnaire

To understand consumer experience within urban poor areas, aligned with Phase One's identified retailer types:

• Employed a cross-sectional design, the study assessed consumer perceptions and behaviors related to the retail food environment, considering socio-demographic factors.
• Urban poor areas in each country were purposively selected, factoring in population density and socio-economic characteristics.
• Retailers were identified using GPS coordinates and mapped, with approximately 10% selected for the study.
• Proportionate stratified sampling aimed to recruit 1000 respondents (aged 18 or older) per country, reporting purchasing from the selected retailers. An intercept survey using the SEAOFE questionnaire was administered in-person or online depending on COVID-19 restrictions, collecting data on socio-demographics, food shopping preferences, and COVID-19 impacts.
• Retailer approval was obtained before data collection.
• Questionnaire translation and pretesting were done before data collection to ensure accuracy.
• Written informed consent was obtained from respondents.

B) Measure discretionary and non-discretionary food products using Audit MAPP-S tool

To assess in-store availability, placement, and promotion of discretionary and non-discretionary food products:

• Monitoring Availability, Placement, and Promotion-Supermarkets (MAPP-S) audit tool was adapted from (Schultz et al., 2021) for each country, and assessed in-store availability, placement, and promotion of discretionary and non-discretionary food products.
• Trained enumerators conducted the audit, ensuring inter-rater reliability.
• Retailer approval was obtained before data collection.