Caffeine Prevalence, Daily Consumption, and Factors Associated with Use among Active Duty United States Military Personnel

Abstract Background: Although representative data on caffeine intake in Americans are available these data do not include US service members (SMs). The few previous investigations in military personnel largely involve convenience samples. This cross-sectional study examined prevalence of caffeine use, daily consumption, and factors associated with use among United States active duty military service members (SMs). Methods: A stratified random sample of 200,000 SMs were asked to complete a questionnaire on their personal characteristics and consumption of caffeinated products. Eighteen percent (n=26,680) of successfully contacted SMs (n=146,365) completed the questionnaire. Results: Overall, 87% reported consuming caffeinated products ≥1 time/week. Mean ± standard error per-capita consumption (all participants) was 218±2 and 167±3 mg/day for men and women, respectively. Caffeine consumers ingested 243±2 mg/day (251±2 mg/day men, 195±3 mg/day women). On a body-weight basis, men and women consumed respectively similar caffeine amounts (2.93 vs 2.85 mg/day/kg; p=0.12). Among individual caffeinated products, coffee had the highest prevalence (68%), followed by sodas (42%), teas (29%), energy drinks (29%) and gums/candy/medications (4%). In multivariable logistic regression, characteristics independently associated with higher use prevalence (≥1 time/week) included female gender, older age, white race/ethnicity, higher body mass index, tobacco use or former use, greater alcohol intake, and higher enlisted or officer rank. Conclusion: Compared to National Health and Nutrition Survey Examination data, daily consumption (mg/day) by SMs was higher, perhaps reflecting higher mental and physical occupational demands on SMs.