Supplemental Nutrition Assistance Program (SNAP) benefits are rapidly depleted after distribution. This phenomenon, known as the benefit cycle, is associated with poor nutrition and health outcomes. However, to date, no study has evaluated trends in food expenditures before and after households receive benefits using prospective data, and whether these trends vary by household characteristics.

Generalised estimating equations were used to model weekly household food expenditures during baseline (pre-benefit) and intervention months by vendor (restaurants and food retailers). Food retailer expenditures were further evaluated by food category (fruits and vegetables and foods high in added sugar). All expenditures were evaluated by household composition, demographics and economic means.

Minneapolis-St. Paul, Minnesota, metropolitan area.

Low-income households (n 249) enrolled May 2013–August 2015.

Weekly food retailer expenditures did not vary during baseline (pre-benefit), but demonstrated a cyclical pattern after households received benefits across all household characteristics and for both food categories, particularly for fruits and vegetables. Households with greater economic resources spent more throughout the month compared with those with fewer resources. Households with lower food security status experienced more severe fluctuations in spending compared with more food secure households.

Cyclical food purchasing was observed broadly across different household characteristics and food categories, with notable differences by household economic means and food security status. Proposed SNAP policy changes designed to smooth food expenditures across the benefit month, such as increased frequency of benefit distribution, should include a focus on households with fewest resources.

The current study aimed to (i) describe racial/ethnic disparities in household food and beverage purchases among participants and non-participants in the Supplemental Nutrition Assistance Program (SNAP) and (ii) examine longitudinal associations between SNAP participation and purchases by race/ethnicity.

To describe disparities, we estimated sociodemographic-adjusted mean purchases of seven unhealthy food and beverage groups (e.g. junk food, sugar-sweetened beverages) and four nutrients (e.g. sugar, Na) among white, black and Hispanic SNAP-participating and non-participating households. To examine longitudinal associations, we used multivariable linear regression with household fixed effects.

USA, 2010–2014.

Food and beverage purchases among low-income (≤250 % federal poverty line) US households (n 30 403) participating in the Nielsen Homescan Panel.

Among non-participants, there were significant black–white disparities (i.e. differences favouring white households) in households’ adjusted mean purchases of processed meat, sweeteners, sugar-sweetened beverages, energy and Na. These disparities persisted among SNAP participants. In contrast, the only significant Hispanic–white disparity among non-participants was for Na purchases; this disparity was reduced in magnitude and no longer significant among SNAP-participating households. Additionally, Hispanic households purchased less energy from junk foods than white households, regardless of SNAP status. In longitudinal models accounting for household fixed effects, SNAP participation was associated with increased energy purchased among black households. No other significant longitudinal associations between SNAP and purchase outcomes were observed.

SNAP may not be meeting its potential to improve food and beverage purchases or reduce disparities. Research is needed to identify strategies for ensuring nutritious purchases across all racial/ethnic groups.