Sugar tax in Poland: population-level trends in obesity, sugar consumption and healthcare utilization

Objective: This ecological study describes population-level trends in obesity, sugar-sweetened beverage (SSB) consumption, per-capita sugar purchases and publicly funded healthcare use for obesity-related conditions in Poland around the introduction of a sugar tax in 2021. Methods: We analyzed nationally aggregated administrative and survey data from the National Health Fund (NHF), the e-Health Center, the Central Statistical Office (CSO) and the National Public Health Institute (NPHI). Annual time series (2014-2024, where available) on per-capita sugar purchases and healthcare use for obesity and major obesity-related comorbidities were evaluated using segmented time-series regression with a 2021 break-point and a COVID-19 (2020) indicator. Survey-based data on SSB and sweets consumption and on overweight and obesity (2018, 2022, 2025), plus cross-sectional BMI data for 2025, were summarized descriptively. Results: Per-capita sugar purchases decreased moderately between 2018 and 2024. Survey data indicated an initial reduction in SSB consumption after 2021, followed by partial rebound by 2025, and a shift towards more frequent sweets consumption, while overweight and obesity continued to rise. For obesity-related conditions, numbers of patients receiving disease-specific healthcare showed a COVID-19-related dip in 2020 and subsequent post-2021 increases, with bariatric surgery and pharmacological treatment of obesity also rising over the study period. Conclusion: In the first 4 years after sugar tax implementation, we observed modest declines in per-capita sugar purchases, transient reductions in SSB consumption and increasing sweets consumption, alongside continued growth in obesity and obesity-related healthcare use. Given the ecological design and short follow-up, these findings represent temporal associations rather than evidence of direct causal effects and underline the need to embed fiscal measures such as a sugar tax within broader, multi-level strategies for obesity prevention, health promotion and access to effective obesity treatment.