Purchasing patterns in low-income neighbourhoods: implications for studying sugar-sweetened beverage taxes.

Objective: The present study aimed to determine the store types from which people in low-income neighbourhoods purchase most sugar-sweetened beverages (SSB) and to identify associations between purchasing location and demographic characteristics.

Design: Street-intercept surveys of passers-by near high foot-traffic intersections in 2016. Participants completed a beverage frequency questionnaire and identified the type of store (e.g. corner store, chain grocery) from which they purchased most SSB.

Setting: Eight low-income neighbourhoods in four Bay Area cities, California, USA.ParticipantsSample of 1132 individuals who reported consuming SSB, aged 18-88 years, who identified as African-American (41 %), Latino (29 %), White (17 %) and Asian (6 %).

Results: Based on surveys in low-income neighbourhoods, corner stores were the primary source from which most SSB were purchased (28 %), followed by discount stores (18 %) and chain groceries (16 %). In fully adjusted models, those with lower education were more likely to purchase from corner stores or discount groceries than all other store types. Compared with White participants, African-Americans purchased more frequently from corner stores, discount groceries and chain groceries while Latinos purchased more frequently from discount groceries.

Conclusions: The wide range of store types from which SSB were purchased and demographic differences in purchasing patterns suggest that broader methodological approaches are needed to adequately capture the impact of SSB taxes and other interventions aimed at reducing SSB consumption, particularly in low-income neighbourhoods.