Objective: To examine overweight and obesity in Australian children followed through to adulthood.
Design and participants: A cohort study of 8498 children aged 7-15 years who participated in the 1985 Australian Schools Health and Fitness Survey; of these, 2208 men and 2363 women completed a follow-up questionnaire at age 24-34 years in 2001-2005.
Main outcome measures: Height and weight were measured in 1985, and self-reported at follow-up. The accuracy of self-reported data was checked in 1185 participants. Overweight and obesity in childhood were defined according to international standard definitions for body mass index (BMI), and, in adulthood, as a BMI of 25-29.9 and > or =30 kg/m2, respectively, after correcting for self-report error.
Results: In those with baseline and follow-up data, the prevalence of overweight and obesity in childhood was 8.3% and 1.5% in boys and 9.7% and 1.4% in girls, respectively. At follow-up, the prevalence was 40.1% and 13.0% in men and 19.7% and 11.7% in women. The relative risk (RR) of becoming an obese adult was significantly greater for those who had been obese as children compared with those who had been a healthy weight (RR = 4.7; 95% CI, 3.0-7.2 for boys and RR = 9.2; 95% CI, 6.9-12.3 for girls). The proportion of adult obesity attributable to childhood obesity was 6.4% in males and 12.6% in females.
Conclusion: Obesity in childhood was strongly predictive of obesity in early adulthood, but most obese young adults were a healthy weight as children.