A new guideline from the Canadian Task Force on Preventive Health Care to help prevent and manage obesity in adult patients recommends body mass index measurement for both prevention and management and structured behavioural changes to help those who are overweight or obese to lose weight. The guideline, aimed at physicians and health care providers, is published in CMAJ (Canadian Medical Association Journal).

Obesity is a substantial public health issue because excess weight is a risk factor for heart disease, diabetes, cancer, arthritis and back pain. In Canada, the number of obese adults has almost doubled since 1978, from 14% to 26%. More than two-thirds of Canadian men (67%) and more than half of women (54%) are overweight or obese.

About two-thirds of overweight and obese adults were of healthy weight as adolescents but gained weight as adults (about 0.5-1.0 kg every 2 years on average); hence, management of even small weight gains is important.

"The creeping pounds add up quickly but often go unnoticed until it's too late," said Dr. Paula Brauer, chair of the task force adult obesity working group. "With excess weight comes the increased risk of several chronic conditions. This is why it is essential for doctors to regularly track patients' weight, and when necessary, discuss a suitable strategy to manage the extra pounds. By doing this, doctors can help their patients mitigate, or ideally, avoid the risks associated with obesity by either preventing or treating the problem."

Key recommendations from the task force:

Body mass index should be calculated at primary health care visits to help prevent and manage obesity.

For normal weight adults, primary care practitioners should not offer formal structured programs to prevent weight gain.

For overweight and obese adults health care practitioners should offer structured programs to change behaviour to help with weight loss, especially to those at high risk of diabetes.

Medications should not routinely be offered to help people lose weight.

Structured behavioural interventions to lose weight involve a series of sessions that focus on making changes to diet, exercise and lifestyle. This approach may include a mix of counselling, education and environmental modifications. The motivation of the patient is a key factor in the success of behavioural interventions.

"Behavioural interventions for overweight and obesity require long-term commitment to change diet and physical activity habits," said Dr. Brett Thombs, a member of the Task Force. "Values and preferences, previous weight loss experiences, personal motivators and barriers, social support and practical resources will affect decisions to undertake intervention. Discussion with the patient is needed to determine the best course of action."

The College of Family Physicians of Canada has endorsed this clinical practice guideline which is based on the best current evidence for preventing and managing obesity.