The effect of food taxes in the UK on health and economic outcomes, and equity: a modelling study

Background

WHO recommends using fiscal policies (such as taxes on unhealthy foods) that discourage consuming foods that contribute to unhealthy diets. Food tax evaluations require consideration for sociodemographic differences, consumer and industry behaviour, reformulation, and long-term health-related outcomes and health inequalities. We aimed to model the potential benefits and harms of three food tax policy designs, to health, costs, and inequalities, in the UK.

Methods

Using a microsimulation model, we performed an economic evaluation of three UK food tax policy designs: (1) a Sugar Snacks tax targeting snacks, cakes, and milk drinks; (2) an Unhealthy Food tax high in fat, sugar, or salt; and (3) a Sugar and Salt tax. Consumption and nutritional changes for a UK representative synthetic population (aged ≥5 years) were estimated by applying a hierarchical Almost Ideal Demand System, accommodating key socio-demographic differences. Our primary analysis simulated outcomes for consumer response only. Secondary analyses incorporated industry responses in the model. The microsimulation estimated changes to weight, cardiometabolic risk factors, lifetime health, discounted National Health Service (NHS) costs, social care costs, unemployment or inactivity, and social benefit receipts.

Findings

The estimated average reduction in daily calorie intake was –25 kcal (95% credible interval [95% CrI]; –31 to –19), –42 kcal (–51 to –33), and –58 kcal (–66 to –50) for the Sugar Snacks, Unhealthy Food, and Sugar and Salt taxes respectively, with reductions in sugar, salt, and saturated fat. Long-term modelling showed improved health, including reduced cardiovascular disease, and type 2 diabetes for all three tax policies. The taxes reduced NHS costs (Sugar Snacks –£168 [95% CrI –461 to –73], Unhealthy Food –£268 [–722 to –105], and Sugar and Salt –£374 [–1033 to –159]) and social care costs. The impact on health inequalities varied by policy design. Only the Sugar and Salt tax had a positive impact on health inequalities.

Interpretation

The overall health impact of each of the three tax policy designs modelled was positive, but it can be associated with important nutritional trade-off—cross-price elasticities led to a reduction in fibre intake. Of the three policies modelled, the Sugar and Salt tax generated the greatest gains and reduced health inequalities. Policy design should consider potential impacts on health inequalities and should be part of a multi-component strategy.

Funding

National Institute for Health and Care Research.