The estimated health and economic impacts of the introduction of taxation and warning labelling on foods high in fat, sugar or salt in England: A microsimulation study

Background: Foods high in fat, sugar, or salt (HFSS) increase risk of obesity and diet-related illnesses. Some policies, limiting HFSS placements, advertisement, and promotion, have been introduced in the UK to lower HFSS exposure, but evidence remains limited on other policy options and their potential impacts. In this study, we estimated the health and economic impacts of implementing taxation and nutrient warning (NW) labelling on HFSS products. Methods: We used the IMPACTNCD, a validated open-cohort microsimulation model, to simulate the health and economic impacts of implementing, for HFSS products, i) 8% taxation, ii) NW labelling, and iii) both combined among English adults aged 30-99 years over 15 years (2026-2040). The IMPACTNCD model utilises nationally representative surveys and routine administrative data to simulate policy and counterfactual scenarios over individuals life course within a competing risk framework. Based on available evidence, we estimated the policy impacts based primarily on assumed consumer-driven changes in energy and salt intake, but also examined likely reformulation in sensitivity analyses. Findings: Compared with the current counterfactual scenario (i.e., no taxation, voluntarily implemented multiple traffic light labelling), an 8% tax rate on HFSS products would reduce obesity prevalence by 2.19 percentage points [95% uncertainty intervals (UI): (1.69, 2.73)], prevent 100 000 [95% UI: (65 000, 140 000)] type 2 diabetes mellitus (T2DM), 83 000 [95% UI: (55 000, 130 000)] cardiovascular disease (CVD), 64 000 [95% UI: (48 000, 96 000)] multimorbidity or multiple long-term condition (MLTC) (i.e., Cambridge Multimorbidity Score >1.5) cases, postpone 23 000 [95% UI: (14 000, 37 000)] deaths, and save a total of 53 billion pounds [95% UI: (41, 67)] from a societal perspective (a sum of healthcare, social care, informal care, and productivity) over 15 years. NW labelling was estimated to reduce obesity prevalence by 0.48 percentage points [95% UI: (0.20, 0.85)], prevent 26 000 [95% UI: (13 000, 52 000)] T2DM, 24 000 [95% UIs: (10 000, 41 000)] CVD, 17 000 [95% UI: (8200, 29 000)] MLTC cases, and postpone 6200 [95% UI: (2200, 12 000)] deaths, and save 14 billion pounds [95% UIs: (6.2, 24)]. Both policies implemented together would provide greater impacts with a 2.66 percentage-point [95% UI: (2.09, 3.28)] reduction in obesity prevalence, 130 000 [95% UI: (80 000, 170 000)] T2DM, 110 000 [95% UI: (68 000, 150 000)] CVD, 81 000 [95% UI: (58 000, 110 000)] MLTC cases prevented, and 29 000 [95% UI: (18 000, 45 000)] deaths postponed, and 66 billion pounds [95% UI: (52, 82)] saved. All modelled policies were estimated to be cost-effective and have greater health benefits for individuals in deprived groups. Sensitivity analysis involving both consumer behaviour and industry reformulation to reduce the number of products classed as HFSS yielded similar estimates. Interpretation: This is the first modelled evidence on the health and economic impacts of HFSS taxation and NW labelling. Implementing both taxation and NW labelling as additional measures to reduce HFSS consumption in the UK may provide substantial benefits in addressing obesity and diet-related diseases.