An umbrella review and narrative synthesis of the effectiveness of interventions aimed at decreasing food prices to increase food quality

BACKGROUND: sustainability of population diet is a public health concern: the high price of healthy food is one of the main causes of diet-related health problems. The aim of this study is to synthesize the evidence produced by systematic reviews that evaluated the effectiveness of decreasing healthy food prices to improve accessibility in order to positively modify the dietary pattern. METHODS: We carried out a review of systematic reviews that examined the effects of the interventions, by exploring the online databases PubMed, Embase, Web of Science, Cochrane Library and hand-searching the reference lists. RESULTS: after screening by titles and abstracts, we selected 11 systematic reviews that met the inclusion criteria, plus one that was hand-searched. The review generally presented a good quality. Studies concluded that measures aimed at modifying the prices of targeted healthy food were effective in improving population diet by modifying what people buy. CONCLUSIONS: the complexity of the outcome-population diet-as well as the poor transferability of data across populations and geographical areas makes it obligatory to provide clear and universal conclusions. Nonetheless, this should not stop policymakers from adapting them and resorting to food fiscal interventions to improve people's diet and health.