Tuesday, April 19, 2005

SPOTLIGHT: Obesity

More of us bulging

ONCE they’re overweight, Canadians are more likely to pack on even more pounds than take them off, according to a new study of obesity among Canadians.

Almost one-quarter of Canadians who had been overweight in 1994/95 had progressed to obesity by 2002/03.

Conversely, only half as many, about 10%, went the other way, that is, returning to their normal weight from obesity.

The net result: more than 1.1 million adult Canadians joining the growing ranks of the obese in less than a decade.

Women, younger men, and members of low-income households were most likely to become obese.

The study used longitudinal data from the National Population Health Survey (NPHS) to follow the same group of people every two years over the eight-year period. At the outset, study participants were aged 20 to 56 and aged 28 to 64 in the final year.

Body mass index

A person is considered overweight if their body mass index (BMI), an approximation of body fat based on height and weight, exceeds 25. They are considered obese when their BMI exceeds 30.

The study focused on the growth in obesity because it has been linked to severe health consequences, including diabetes, cardiovascular disease, osteoarthritis and some forms of cancer.

The study supports findings from previous research, and what many people have already discovered, that it appears easier not to put weight on in the first place than it is to take it off. As a result, interventions that focus on prevention may be more effective than loosing weight programs.

The weight gain was not limited to overweight Canadians. The study documented that during the eight years, one-third of people who started out in the normal weight range became overweight.

Tougher for women

Men were more likely than women to make the transition from a normal weight to being overweight. At the end of the eight years, 38% of the men whose weight was normal in 1994/95 had become overweight, compared to 28% of the women.

However, women were more likely to go from being overweight to being obese. By 2002/03, 28% of the women who had been overweight became obese, compared to 20% of the men.

This translated into more than 600,000 new cases of obesity in less than a decade for men, compared to almost 500,000 new cases for women.

You can read the article “Obesity: A growing issue” free on our website.

For more information, contact Christel Le Petit (613-951-3856), Health Analysis and Measurement Group.

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© 2004, 2005 Statistics Canada.