Evidence-Based Clinical Practice Guidelines for the Management of Obesity

David C. W. Lau, MD, PhD, FRCPC

David C. W. Lau, MD, PhD, FRCPC: Department of Medicine, Biochemistry and Molecular Biology, Julia McFarlane Diabetes Research Centre, University of Calgary, Calgary, Alberta

Address for correspondence: David C. W. Lau, MD, PhD, FRCPC, Room 2521, Julia McFarlane Diabetes Research Centre, Health Sciences Centre, 3330 Hospital Drive NW, Calgary, AB T2N 4N1; E-mail: dcwlau@ucalgary.ca

Conflict of interest: None declared

Can J Gen Intern Med 2006;1:XX–XX

ABSTRACT

The prevalence of childhood and adult obesity continues to increase in Canada. One in four adults have a BMI >30, and our children are becoming increasingly obese too. Associated co-morbidities, particularly diabetes, place a significant burden on personal well-being and health care costs. Obesity Canada, an organisation founded in 1999, plans to tackle the obesity epidemic with practical treatment and prevention guidelines.

The prevalences of overweight and obesity continue to increase in Canada in both children and adults, and in all areas of the country. Data from the 2004 Canadian Community Health Survey indicate that over half of the adult population is overweight (body mass index [BMI] greater than or equal to 25 kg/m2), while one in four adults is obese (BMI greater than or equal to 30 kg/m2).1 These numbers highlight a pressing public health problem that shows no signs of improving in the near future. Obesity among Canadian children and adolescents is advancing at an even more rapid pace than that seen in adults. In 2004, one in four Canadian children and adolescents (ages 2 to 17) was overweight. In the past 15 years, the obese rate has dramatically increased from 2 to 10% in boys and from 2 to 9% in girls.2,3 This is of particular concern, given the tendency for obese children to become obese adults. Moreover, obesity-related health problems, notably type 2 diabetes, now occur at a much earlier age and continue to progress into adulthood.4

We can no longer view obesity as a mere cosmetic or body image issue. There is compelling evidence that overweight individuals have an increased risk of developing a variety of health problems, including type 2 diabetes, hypertension, dyslipidemia, coronary heart disease, stroke, osteoarthritis, and certain forms of cancer.4 It has recently been estimated that approximately 1 in 10 premature deaths among Canadian adults 20 to 64 years of age is directly attributable to overweight and obesity. The cost of obesity in Canada has been conservatively estimated to be $2 billion a year, or 2.4% of the total health care expenditures in 1997.5 In addition to impacting personal health, these increased health risks translate into an increased burden on the health care system.

The etiology of obesity is complex and multifactorial. Within the context of environmental, social, and genetic factors, at the simplest level, obesity results from long-term positive energy balance, influenced by the imbalance of energy intake and energy expenditure. The rapid increase in the prevalence of obesity over the past 20 years has a basis in environmental and cultural factors, rather than genetic ones. Adipose tissue has been recognized as an important endocrine organ, one that releases a large number of adipokines and contributes to the development of the metabolic syndrome.6 As standards of living in developed and developing countries improve, overnutrition and sedentary lifestyle supplant physical labour and regular physical activity; the result is a positive energy balance and weight gain.7

Considerable advances have been made in dietary, exercise, behavioural, pharmacological, and bariatric–surgical approaches to successful long-term management of obesity. A modest weight loss of 5 to 10% can significantly improve metabolic co-morbidities and health status.7 While lifestyle intervention remains the cornerstone treatment of obesity, adherence rate is poor and long-term success is modest. This is a consequence of patient factors and physician attitudes to treatment. Pharmacotherapy and bariatric surgery are useful treatments, but for a variety of reasons they are not widely adopted.7

Despite our steady progress in successful obesity management, the prevalence of obesity continues to rise. Prevention and intervention strategies are required to slow, and hopefully reverse, this alarming trend. Population interventions to date have tended to focus on individual risk factors and have been largely ineffective. Simple and practical guidelines for the busy practitioner are desperately needed.

A number of clinical practice guidelines (CPGs) have been published, but these were largely developed on the basis of consensus statements by an expert panel. Most of these guidelines focused on individuals rather than on communities and populations. Recognizing these deficiencies, Obesity Canada, a not-for-profit organization, was founded in 1999 with a goal of tackling the obesity epidemic. CPGs for the treatment and prevention of childhood and adult obesity are being written. Members of the steering committee and expert panel have also identified major gaps in knowledge in this area, and the need for a considerable research effort. This will include enhanced surveillance and population-based data; new research on the biological, social, cultural, and environmental determinants of obesity; and research on effective treatment strategies, policies, and interventions.

As obesity is increasingly viewed as a societal issue, the steering committee and expert panel members unanimously agreed to include sections on the prevention of obesity in children and adults at the population level, as well as implications of the CPGs for health policy makers and other interested parties.

As knowledge flows from new research, the Canadian CPGs for the management and prevention of obesity will be strengthened. We hope that, as a consequence of their implementation, Canadians will enjoy a slimmer and healthier future.

References

1.            Shields M. Findings from the Canadian Community Health Survey: Statistics Canada. Nutrition 2005;1.

2.            Shields M. Measured obesity: overweight Canadian children and adolescents. Ottawa: Statistics Canada; 2005.

3.            Tremblay MS, Willms JD. Is the Canadian childhood obesity epidemic related to physical inactivity? Int J Obes Relat Metab Disord 2003;27:1100-5.

4.            Lau DCW, Yan H, Dhillon B. Metabolic syndrome: a marker of patients at high cardiovascular risk. Can J Cardiol 2006;22(Suppl B):85-90B.

5.            Birmingham CL, Muller JL, Palepu A, et al. The cost of obesity in Canada. CMAJ 1999;160:483-8.

6.            Lau DC, Dhillon B, Yan H, et al. Adipokines: molecular links between obesity and atherosclerosis. Am J Physiol Heart Circ Physiol 2005;288(5):H2031-41. Epub.

7.            Lau DCW. Obesity. In: Gray J, ed. Therapeutic Choices, 4th edition. Ottawa: Canadian Pharmacists Association; 2003:1096-101.