Trends in weight change among Canadian adults.

Longitudinal analyses were used to examine the rate of change of self-reported weight among adults over two-year intervals from 1996/1997 to 2004/2005, and to determine if the pace at which Canadians' weight is changing has slowed down or accelerated. Associations between weight change and sex, age group and body mass index (BMI) category arealsoexamined.The data are from the 1996/1997 through 2004/2005 National Population Health Survey.Average weight changes over two-year intervals were calculated by sex, age group and BMI category. Linear regression was used to determine if the rate of weight change was stable, increased or decreased over time.From 1996/1997 to 2004/2005, Canadian adults gained, on average, 0.5 to 1 kg per two-year period. Although people aged 18 to 64 continued to gain weight, the amount gained decreased significantly in the most recent interval, 2002/2003 to 2004/2005. This downturn is due, in part, to a significant decrease in the proportion of men gaining weight during that period. However, among people who gained weight, the amount gained in two years increased over the entire eight-year period.