The prevalence of childhood obesity has increased dramatically over the past two decades in both developed and developing countries(Reference Wang and Lobstein1), with approximately 110 million children now classified as overweight or obese(Reference Haslem and James2). The incidence of obesity at an early age frequently persists into adulthood and is associated with increased morbidity and mortality in later life(Reference Dietz3). A study conducted in Northern Ireland over a decade ago reported a 15.7% prevalence of overweight and obesity in boys and 16.0% for girls(Reference Yarnell, McCrum and Patterson4). However, little recent data exist for current trends in body weight of schoolchildren in Northern Ireland.
A total of 2648 children were randomly selected from twenty-four secondary and grammar schools in Northern Ireland (mean age 13.6 (sd 0.7) years) to participate in an ongoing international study designed to measure the prevalence of asthma and allergies. All children completed a questionnaire that included a food frequency section and they provided anthropometric measurements.
Using international guidelines on defining underweight, overweight and obesity in children(Reference Cole, Bellizzi and Flegal5, Reference Cole, Flegal and Nicholls6), the prevalence of underweight in boys was 4.6%, with 17.9% being overweight and 6.0% being obese. In girls 5.5% were underweight, 22.8% were overweight and 6.4% were obese. As shown in the Table, of the girls who were overweight and obese 26% were following a weight-reducing diet (mostly self-prescribed) compared with 15% of boys. On examining social class, a significant trend was observed between the parent or guardian with the highest social class and height for both boys and girls (P<0.001 and P=0.007 respectively) and for BMI for girls only (P=0.009).
Table. Number and percentage of schoolchildren aged 12–15 years on self-prescribed or medical weight-reducing dietsFootnote *
* Data unavailable for twelve boys and twenty-nine girls.
The present study provides evidence of an increase in overweight and obesity among schoolchildren from Northern Ireland over the last decade. The greatest increase was observed among girls, for whom the prevalence of overweight and obesity had doubled. However, girls appeared to have a greater awareness of and/or concern about their weight, as a greater number reported being on a weight-loss diet.
