Ten-year trends for fatness in Northern Irish adolescents: the Young Hearts Projects - repeat cross-sectional study

OBJECTIVE: To examine secular trends in measures of fatness over a 10-y period (the 1990s) in Northern Irish schoolchildren. DESIGN: Repeat cross-sectional surveys. SUBJECTS: In total, 12- and 15-y-old children randomly selected from post-primary schools. A total of 1015 children studied between 1989 and 1990, and 2017 studied between 1999 and 2001. MEASUREMENTS: The same study methods were applied in both surveys. Body mass index (BMI) was calculated from height and weight, and percentage body fat (% BF) was derived from skinfold measurements at four sites. Dietary intake was assessed using a diet history method and habitual physical activity ( PA) was estimated from a self-report questionnaire. RESULTS: Increases were seen in both height and weight in all age - sex groups. The overall prevalence of overweight/obesity increased from 15.0 to 19.6%, but 12-y-old girls contributed most to this increase (15.9 - 26.3%), with a modest increase observed also in 15-y-old boys. Increases in mean BMI (19.2 - 20.3 kg/m(2)) and mean % BF (25.8 - 27.1%) were seen in 12-y-old girls, with no significant changes in any of the other subgroups. Mean energy intake increased in girls but not in boys, while mean PA score decreased in 12-y-old girls, but was unchanged in the other three groups. All age - sex groups showed substantial increases in the sugar intake while fat intake increased in girls and decreased in boys. CONCLUSION: Increases in indices of fatness were seen among school-age children in Northern Ireland during the 1990s. Trends differed between age-sex groups with the largest changes seen in 12-y-old girls. It remains to be seen whether the large increase in overweight/obesity in this group tracks into adulthood, with consequences for chronic disease incidence in women. International Journal of Obesity (2005).