Beverage-based caffeine intake and high consumption trends among Korean adults, 2016–2024: a nationwide population-based study

Background Caffeine is the most widely consumed psychoactive substance worldwide, yet nationally representative evidence on long-term consumption trends remains limited in Korea. This study aimed to evaluate temporal trends in beverage-derived caffeine intake among Korean adults between 2016 and 2024, identify major beverage sources, and examine demographic factors associated with high caffeine intake (≥400 mg/day). Methods Data were obtained from the 7–9th Korea National Health and Nutrition Examination Surveys. We included adults aged ≥19 years with valid 24-h dietary recall data. Caffeinated beverages were identified using beverage food codes and product information recorded in the dietary database and classified into five categories: coffee, tea, energy drinks, cola-type beverages, and cocoa-based beverages. Daily caffeine intake was estimated using beverage-specific caffeine concentrations derived from national monitoring data. Survey-weighted linear and logistic regression models accounting for the complex sampling design were used to assess temporal trends and associations with high caffeine intake. Results Among 48,991 adults, mean daily caffeine intake increased over time (β = 1.66 mg/day per year; 95% CI, 1.05–2.27), and the odds of high caffeine intake also increased (OR = 1.05 per year; 95% CI, 1.02–1.07). Coffee was consumed by 90.8% of caffeine consumers, with a shift from coffee mixes toward brewed coffee. Women aged 30–44 years had higher odds of high caffeine intake (aOR = 1.62; 95% CI, 1.21–2.16), whereas adults aged ≥65 years had lower overall odds (men: aOR = 0.37; 95% CI, 0.25–0.53; women: aOR = 0.23; 95% CI, 0.12–0.44). Conclusions Caffeine intake among Korean adults has increased, driven by shifts in coffee consumption. The rising odds of high caffeine intake among working-age adults highlights the need for continued surveillance and targeted public health guidance.