Assessing caffeine intake in the United Kingdom diet.

Caffeine occurs naturally in the leaves and seeds of many plants and is artificially added to some beverages. Consumption of caffeine has been linked to both positive and adverse health outcomes. We incorporated estimates of caffeine content (mg/100g or ml) of foods and drinks, taken from the published literature, to provide a preliminary estimate of caffeine intake for the UK population, based on data collected in the National Diet and Nutrition Survey 2008-10. Among consumers mean total caffeine intakes of adult men 19+ y were significantly greater than intakes by boys 4-10y and 11-18y (p<0.05), with the same age-related differences seen for females. 4.1% of men 19+ y and 3.8% of women 19+ y had caffeine intakes in excess of 300mg/d. The addition of caffeine to UK food composition databases will allow more detailed study of the health effects of caffeine consumption.