What sort of teenager has high intakes of energy and nutrients?

1. An alternative statistical technique, based on analysis of the 75th percentile, was used to examine teenagers' diets. The technique was developed to identify personal characteristics that affected the prevalence of high energy and nutrient intakes. It provided useful information not obtainable from methods based on average intakes. 2. The study sample was a representative sample of 1055 high-school students in Tasmania, Australia, aged 11–16 years. 3. Among girls, the prevalence of high intakes of energy and several nutrients was not affected by any of the fifteen characteristics studied. (In this context, ‘high’ was defined as above the 75th percentile for girls.) Fatter, heavier girls were less likely to have high intakes of carbohydrate, iron and niacin-equivalent, and also of meat and ‘empty-energy’ foods. Girls from small families were less likely to have high calcium intakes, and girls from goverment schools less likely to have high thiamin intakes. 4. Among boys, age generally had the greatest influence on the prevalence of high intakes (‘high’ being defined as above the 75th percentile for boys). Older boys were more likely to have high intakes of energy and most nutrients, as well as meat, cereals and fruit and vegetables. These age-related changes were, however, rather asynchronous. High fat intakes were more common among boys wbo had drunk more than five glasses of alcoholic beverages in the preceding week. High Ca intakes were more frequent among those who exercised vigorously, and high vitamin A intakes less common among the sons of well-educated mothers.