Nutrition quality of food purchases varies by household income: the SHoPPER study

TLDR

Lower household income is consistently linked to poorer diet quality, and household food purchases represent a key intervention target to improve diet among low‑income populations. The study examined associations between household income and the diet quality of food purchases by collecting 14‑day purchase receipts from 202 urban households and analyzing them with NDS‑R software, scoring using the Healthy Eating Index 2010, and evaluating HEI totals, subscores, and grocery dollar proportions across income‑to‑poverty ratios. Higher‑income households achieved significantly higher HEI total scores, better vegetable and dairy subscores, and spent fewer dollars on frozen desserts, whereas lower‑income households purchased less healthful foods. Food purchasing patterns may mediate income differences in dietary intake quality; the study is registered under ClinicalTrials.gov NCT02073643.

Abstract

Lower household income has been consistently associated with poorer diet quality. Household food purchases may be an important intervention target to improve diet quality among low income populations. Associations between household income and the diet quality of household food purchases were examined.Food purchase receipt data were collected for 14 days from 202 urban households participating in a study about food shopping. Purchase data were analyzed using NDS-R software and scored using the Healthy Eating Index 2010 (HEI 2010). HEI total and subscores, and proportion of grocery dollars spent on food categories (e.g. fruits, vegetables, sugar sweetened beverages) were examined by household income-to-poverty ratio.Compared to lower income households, after adjusting for education, marital status and race, higher income households had significantly higher HEI total scores (mean [sd] = 68.2 [13.3] versus 51.6 [13.9], respectively, adjusted p = 0.05), higher total vegetable scores (mean [sd] = 3.6 [1.4] versus 2.3 [1.6], respectively, adjusted p < .01), higher dairy scores (mean [sd] = 5.6 [3.0] versus 5.0 [3.3], p = .05) and lower proportion of grocery dollars spent on frozen desserts (1% [.02] versus 3% [.07], respectively, p = .02).Lower income households purchase less healthful foods compared with higher income households. Food purchasing patterns may mediate income differences in dietary intake quality.ClinicalTrials.gov identifier: NCT02073643.