Canada tackles growing obesity epidemic

The first-ever Canadian Clinical Practice Guidelines (CPG) on the Management and Prevention of Obesity in Adults and Children, published April 10, 2007 in the Canadian Medical Association Journal (CMAJ), recommend that waist circumference be measured in all Canadian adults, and that a national surveillance system be developed that incorporates this measurement along with height and weight.

This represents a landmark publication, as Canada is the first country in the world to produce comprehensive evidence-based guidelines to address the management and prevention of overweight and obesity in adults and children. These are also important guidelines for health professionals and policy-makers to help them address Canada's increasing prevalence rates.

The guidelines were developed by a panel of experts from across Canada, who identified a need for a comprehensive set of clinical guidelines to provide health care practitioners with a toolkit to manage and treat overweight and obese patients, as well as those who have a high waist circumference. Furthermore, the panel identified gaps in existing knowledge, and new research requirements needed to help develop a greater understanding of weight and body shape and their link to chronic diseases such as cardiovascular disease and diabetes.

"As obesity has become a major health care concern in Canada, the experts agreed that this can no longer be regarded as a cosmetic or body image issue," says Dr. David Lau, President of Obesity Canada, Chair of the CPG Steering Committee and a professor medicine at the University of Calgary. "Furthermore, we've identified recommendations for treating this medical problem as a societal issue that requires support from all levels of the community, from health care teams to schools to all levels of government."

CMAJ Editor-in-Chief Dr. Paul H'bert notes that these guidelines not only give practical recommendations for health professionals, "but also identify knowledge gaps between what is known and what is needed to identify, prevent and treat obesity and its consequences."

The recommendation for measuring the waist circumference of all adults is the result of the latest research indicating that fat in the abdominal area is linked to an increased risk of cardiovascular disease and diabetes.

The guidelines reference the International Diabetes Federation (IDF) cut-off points for waist circumference, given that these measures better reflect the ethnic diversity of Canada. Using IDF criteria, over 50% of Canadians are considered abdominally obese.

"While many Canadians are stepping on the scale to monitor their weight, we're now finding that it is just as important for them to measure their waistline to determine if they are at risk for diabetes and heart disease," says Dr. Lau. "Health care practitioners need to take the lead and measure their patients' waist circumference, as this is a 'new vital sign' that's just as important as taking blood pressure, and measuring lipid and blood sugar levels."

The guidelines also recommend that:

• First-line treatment for overweight and obese adults should consist of diet changes and regular exercise, supported by behaviour change; if unsuccessful, treatment with medications or bariatric surgery should be considered;
• Starting at 10 years of age, overweight or obese Canadians should undergo screening that would include tests measuring levels of fasting glucose, HDL (the good) and LDL (the bad) cholesterol, and triglycerides (a form of fat in the blood) levels. Furthermore, they should be monitored at regular intervals;
• Patients participating in weight management programs should be provided with education and support in behaviour modification techniques as an add-on to other lifestyle modifications;
• Programs to promote healthy, active living and to prevent overweight and obesity should be implemented in schools to reduce the risk of childhood obesity; these include interventions to increase daily physical activity through physical education class-time and opportunities for active recreation;
• "Screen time" (e.g. television watching, and video or computer games) should be limited to less than two hours per day to encourage increased activity and less food consumption, and to limit exposure to food advertising.

"We hope that our recommendations will have a major impact on guiding health care practitioners to work with their patients to help them understand that weight and body shape is not a cosmetic issue but a medical issue," says Dr. Denis Drouin, Clinical Professor of Family Medicine at Laval University in Qubec City and a member of the CPG Expert Panel.

"Canadians must be alerted to the fact that their weight and body shape can have a serious impact on their long-term health, and that they need to act now to lessen their risk of heart disease and diabetes. Even a modest loss of 5% to 10% of body weight, or a few inches from the waist, can result in significant health benefits."

As there remain major gaps in knowledge regarding treatment and prevention, the guidelines also recommend areas for further research to optimize management and to reduce the prevalence rate of overweight and obese individuals in Canada.

The recommendations range from the need for population based data and more research on the biological, social, cultural and environmental determinants of obesity, to new research on effective treatment strategies, policies and interventions.