The Effects of Subsidies for Healthy Foods on Food Purchasing Behaviors, Consumption Patterns, and Obesity/Overweight: A Systematic Review.

Context: Taxing unhealthy foods and drinks is an essential measure against the double burden of malnutrition that affects every nation worldwide. In turn, subsidizing the consumption of healthy foods can also be a critical measure for changing the population's behavior and improving health indicators.

Objective: A systematic review was conducted of food subsidies and their potential impact on food purchases, consumption, overweight/obesity, and changes in body mass index (BMI).

Data sources: The PubMed, Embase, LILAC, Scientific Electronic Library Online, and Google Scholar databases were searched to identify studies investigating the effects of subsidies on the amount of food purchased, food consumption, caloric intake, nutrient intake, and their impact on overweight, obesity, and BMI changes. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist.

Data extraction: Two investigators independently performed data screening, extraction, and quality assessment.

Results: Of the 6135 studies screened, 149 were read in full and 18 were included in this systematic review. Most studies investigated the effects of subsidy scenarios on food purchases and observed increases in fruit and vegetable (F&V) purchases when these were subsidized. In randomized controlled studies, subsidized healthy foods were purchased more often. However, when the subsidy was suspended, F&V consumption decreased. Although quasi-experimental studies have demonstrated increased F&V consumption due to subsidies, some studies showed increased saturated fat and sodium intake. Only 2 studies evaluated the relationship between subsidies and obesity, yielding conflicting results.

Conclusion: Although the subsidies appear to encourage purchase and consumption of healthier foods, enhancing the quality and diversity of dietary choices, the removal of subsidies can lead to a decline in the consumption of healthier foods. Additionally, their impact on obesity and BMI remains uncertain and requires further research.

Systematic review registration: PROSPERO registration by the number CRD42023442122.