Obesity

Is obesity the new smoking? It seems everywhere we turn, there is cause for worry, because the facts are stark and the message blunt. Most of us, and our kids, need to drop some weight to live better and longer. As we become more aware of the effects of excess weight, the better able we will be to manage it.

The 2004 Canadian Community Health Survey (CCHS), recently released by Statistics Canada, is full of weighty numbers:

In 2004, 23% of (5.5 mm) Canadian adults were obese (BMI>30); 36% (8.6 mm) more were overweight. Based on actual measurements (much more reliable than self-reported data) almost 60% of us are in trouble. The obesity figure was 15% in 2003 when height and weight data were self-reported.
The percentage aged 25-34 who reported obesity more than doubled, from 8.5% in 1978-79, to 20.5% in 2004. This change doesn’t augur well for the future, since adults tend to add weight (but not height!) as they age.
Overall rates of obesity were the same for men and women, but women are more likely to be extremely obese (BMI>40), where the risk of developing health problems is considered much higher.
The prevalence of obesity is related to food intake (especially a lack of fruit and vegetables) and exercise levels.
Excess weight is a risk factor for diabetes, cardiovascular disease, hypertension, osteoarthritis, some cancers, and gall bladder disease. Psychosocial problems and functional limitations are also associated with obesity.

Diabetes

Just over 2% of normal-weight men had diabetes. The figure rose to 3.7% for men who were overweight, and 11% for those who were obese. The figures were similar for women.

Cardiovascular disease

Just under 3% of normal-weight men reported heart disease, versus 6% for those who were overweight and almost 8% for those who were obese. For women, there was no significant difference in rates of heart disease for normal weigh (3%) and overweight (4%). The female rate jumped to 7% when BMI exceeded 30, but dropped slightly (to 6%) for the most obese.

Hypertension

Less than 10% of Canadian adults of normal weight had high blood pressure, compared to 15% of those who were overweight, and 20% of those who were obese.

For all three diseases, prevalence is anywhere from 50% to 200% higher for those who are overweight, and twice to five times higher for those who are obese.

The future does not look bright for our children:

63% are not active enough for optimal growth and development,
63% of obese children become obese adults, and
40% have lapsed into inactivity, and are therefore at risk of cardiovascular disease. (*)
Between 1981 and 2001, the rates of overweight and obesity among Canadian boys doubled, and quintupled for girls. (**)

In most reports, including the CCHS, excess weight is measured by Body Mass Index (BMI). BMI is reasonably easy to calculate and tables are widely available, but it has a number of limitations. BMI may not be accurate for those who are very lean or muscular, very tall or short, or people from certain ethnic or racial groups.

As well, BMI does not measure the distribution of fat. There is an emerging view among researchers that a simple waist measurement is a better predictor of health risk. Currently, for most North Americans, a waist measurement over 88 cm for women and 102 cm for men presents a significantly higher risk for cardiovascular events. Those who are "apple-shaped" are known to have higher risk than those who are "pear-shaped". Excess abdominal fat close to the vital organs may be worse than if deposited elsewhere.What’s the bottom line? If you or someone in your family is overweight, seriously consider making a change. First, consult a doctor and perhaps a dietitian. Once personal motivation is strong and lifestyle changes are underway, medications may help. Changing behaviour is tough, but the good news is that even modest (5%-10%) reductions in weight can significantly improve health status.

Sources: Facts from Statistics Canada, 2005. 2004 Canadian Community Health Survey (CCHS), unless otherwise noted. (*) Dr Andrew Pipe, University of Ottawa Heart Institute at the Ontario Hospital Association Convention, Nov 2005. (**) Canadian Institute for Health Information 2004; Improving the Health of Canadians.