Caffeine use among active duty US Army soldiers.

Eighty-percent of the US adult population regularly consumes caffeine, but limited information is available on the extent and patterns of use. Caffeine use is a public health issue and its risks and benefits are regularly considered in scientific literature and the lay media. Recently, new caffeine-containing products have been introduced and are widely available on Army bases and are added to rations to maintain cognitive performance. This study surveyed caffeine consumption and demographic characteristics in 990 US Army soldiers. Data were weighted by age, sex, rank, and Special Forces status. Total caffeine intake and intake from specific products were estimated. Logistic regression was used to examine relationships between caffeine use and soldier demographic and lifestyle characteristics. Eighty-two percent of soldiers consumed caffeine at least once a week. Mean daily caffeine consumption was 285 mg/day (347 mg/day among regular caffeine consumers). Male soldiers consumed, on average, 303 mg/day and females 163 mg/day (regular consumers: 365 mg/day for male soldiers, 216 mg/day for female soldiers). Coffee was the main source of caffeine intake. Among young males, energy drinks were the largest source of caffeine intake, but their intake was not greater than older males. Regression analysis indicated an association of higher caffeine intake with male sex, white race, and tobacco use (P<0.01). Most soldiers consume caffeine in levels accepted as safe, but some consume greater quantities than recommended, although definitive information on safe upper limits of caffeine intake is not available. Labels of caffeine-containing products should provide caffeine content so individuals can make informed decisions.