Higher nutritional quality at no additional cost among low-income households: Insights from food purchases of “positive deviants

Background: It is unknown whether diet quality is correlated with actual food expenditure. According to the positive deviance theory, the study of actual food expenditure by people with limited economic resources could help identify beneficial food-purchasing behavior. Objectives: The aims were to investigate the relation between ac-tual expenditure on food and nutritional quality and to identify “positive deviants ” among low-income households. Design: Individuals in deprived social situations (n = 91) were re-cruited as part of the “Opticourses ” nutrition intervention conducted in 2012–2014 in poor districts of Marseille, France. Opticourses partici-pants collected food-purchase receipts for their household over a 1-mo period. “Actual diet costs ” and “estimated diet costs ” were calculated per 2000 kcal of food purchases by using actual expenditures and a standard food price database of food consumed by a representativ