The effect of subsidies on healthful consumption: Systematic review and data synthesis

Abstract

Background: Prevalence of obesity and overweight has risen to the level of an epidemic. Health policy makers are seeking evidence-based solutions to this problem. This study reviews evidence on the subsidization of healthy foods as a fiscal tool to aid in the public health response to this epidemic. Methods: A systematic search of the major databases was performed, and data extracted from studies meeting inclusion criteria. Main outcomes of interest were indicators of purchasing/consumption pattern, or body composition. Preliminary results are presented as a narrative summary. Results: Search results yielded 22 studies, of which 10 were extracted and 12 excluded. Of the 12 excluded 5 were duplicate studies of reports extracted, and 7 studies did not meet inclusion criteria. Most extracted studies were randomized control trials. The majority of the studies had multiple arms, one of which was typically a multi-component fiscal measure implemented alongside education or skills building. This type of multi-component intervention yielded the most promising results, mainly an increase in the percentage of daily fruit and/or vegetable consumption. This percentage increase varied between studies ranging from 4% up to 35%, with fruit consumption/purchasing responding more favorably to pricing changes compared to vegetable consumption/purchasing. Conclusion: Although preliminary, the results suggest that multi-component interventions appear to be the most promising in terms of real changes to purchasing behavior. Important considerations include the significant heterogeneity in reported outcomes, and the notable lack of studies assessing for substitution effects. Policy makers, in their examination of these findings, should consider these limitations