Caffeine Consumption in Polish Adults: Development and Validation of a Polish Questionnaire for Assessing Caffeine Intake

Objective: Caffeine is one of the oldest natural substances consumed by people. Its consumption in Poland has not been well described. The aim of this study was to design and validate an online food frequency questionnaire (FFQ) on caffeine intake and to use it to estimate caffeine consumption in Polish adults.Method: The FFQ was prepared and validated in a pilot study. The intake assessment was conducted in 2019-2020 on 372 respondents, aged 18 to 60 years. The FFQ included products such as coffee, tea, energy drinks, and carbonated drinks, as well as supplements and chocolate.Results: We showed good repeatability of the FFQ and it was considered a valid tool. The mean total caffeine intake among all participants was 426.7 mg ± 283.4 mg/day of all sources; in women, it was 446.4 mg ± 306.2 mg/day, while in men, it was 394.1 ± 236.4 mg/day. Forty-three percent of the respondents consumed more than 400 mg of caffeine/day. Coffee was the main source of caffeine and contributed to 65% of total caffeine consumption. Women consumed 90% more green tea than men (p < 0.01). Overweight and obese people have 20% greater total caffeine intake (p = 0.01) and consumed 20% more coffee (p = 0.02) and 30% more black tea (p = 0.01) than people of normal weight.Conclusions: Average caffeine consumption among Polish adults slightly exceeds the safe consumption dose established by the European Food Safety Authority. Body weight status can differentiate caffeine intake.