Objective: To assess changes in the prevalence of overweight and obesity among Canadian children and adults between 1981 and 1996 using recent recommendations for the classification of overweight and obesity.
Design: Epidemiological study comparing the prevalence of overweight and obesity from the 1981 Canada Fitness Survey (CFS) to the 1996 National Longitudinal Survey of Children and Youth (NLSCY) and the 1996 National Population Health Survey (NPHS).
Subjects: Adults 20-64 y of age and children 7-13 y of age from the CFS, NLSCY and NPHS.
Measurements: BMI was calculated from directly measured or self-reported body mass and height. For adults 20-64 y of age, overweight and obesity were defined as BMI > or = 25 kg/m2 and BMI > or = 30 kg/m2, respectively. Age- and sex-specific cut-off points for children that correspond to the adulthood categories were used to define overweight and obesity for children 7-13 y of age.
Results: The prevalence of overweight increased from 48 to 57% among men and from 30 to 35% among women, while the prevalence of obesity increased from 9 to 14% in men and from 8 to 12% in women. The corresponding increases were from 11 to 33% in boys and from 13 to 27% in girls for overweight and from 2 to 10% in boys and from 2 to 9% in girls for obesity.
Conclusion: The results indicate dramatic increases in the prevalence of both overweight and obesity in Canada over the last 15 y, and the problem is particularly pronounced among children.