To assess the effect of food taxes and subsidies on diet, body weight and health through a systematic review of the literature. We searched the English-language published and grey literature for empirical and modelling studies on the effects of monetary subsidies or taxes levied on specific food products on consumption habits, body weight and chronic conditions. Empirical studies were dealing with an actual tax, while modelling studies predicted outcomes based on a hypothetical tax or subsidy. Twenty-four studies met the inclusion criteria: 13 were from the peer-reviewed literature and 11 were published on line. There were 8 empirical and 16 modelling studies. Nine studies assessed the impact of taxes on food consumption only, 5 on consumption and body weight, 4 on consumption and disease and 6 on body weight only. In general, taxes and subsidies influenced consumption in the desired direction, with larger taxes being associated with more significant changes in consumption, body weight and disease incidence. However, studies that focused on a single target food or nutrient may have overestimated the impact of taxes by failing to take into account shifts in consumption to other foods. The quality of the evidence was generally low. Almost all studies were conducted in high-income countries. Food taxes and subsidies have the potential to contribute to healthy consumption patterns at the population level. However, current evidence is generally of low quality and the empirical evaluation of existing taxes is a research priority, along with research into the effectiveness and differential impact of food taxes in developing countries.

The World Health Organization has recommended that Member States consider taxing energy-dense beverages and foods and/or subsidizing nutrient-rich foods to improve diets and prevent noncommunicable diseases. Numerous countries have either implemented taxes on energy-dense beverages and foods or are considering the implementation of such taxes. However, several major challenges to the implementation of fiscal policies to improve diets and prevent noncommunicable diseases remain. Some of these challenges relate to the cross-sectoral nature of the relevant interventions. For example, as health and economic policy-makers have different administrative concerns, performance indicators and priorities, they often consider different forms of evidence in their decision-making. In this paper, we describe the evidence base for diet-related interventions based on fiscal policies and consider the key questions that need to be asked by both health and economic policy-makers. From the health sector's perspective, there is most evidence for the impact of taxes and subsidies on diets, with less evidence on their impacts on body weight or health. We highlight the importance of scope, the role of industry, the use of revenue and regressive taxes in informing policy decisions.

During the past decade, dozens of countries, regions, and cities have enacted taxes on sugar-sweetened beverages (SSBs). They have been primarily motivated by a desire to raise prices, reduce sales and consumption, improve population health, and raise revenue. This review outlines the economic rationale for SSB taxes and illustrates their predicted effects. It reviews the research on the effects of these taxes on retail prices, sales, cross-border shopping, consumption, and product availability. The evidence indicates that the amount by which taxes increase retail prices (also called the pass-through of the tax) varies by jurisdiction, ranging from less than 50% to 100% of the tax. Sales tend to decrease significantly in the taxing jurisdiction, although this seems to be partly offset by residents increasingly shopping outside of the taxing jurisdiction (i.e., engaging in cross-border shopping).Overall, taxes lower consumption of the taxed beverages by adults, although not for all types of beverages or all groups of consumers. We conclude with suggestions for improving the design of such taxes and directions for future research.