Obesity Research in Canada

Backgrounder

[ Press Release 2004-02 ]

Obesity - A Priority Concern

National and international medical journals and popular media tell us that obesity is a priority concern for governments, health researchers and average citizens around the world. And little wonder -- obesity, and its related health disorders and impacts, is a complex and challenging health issue with grave implications for individuals and whole populations. In Canada, a conservative estimate of the total direct cost of overweight and obesity was $1.8 billion in 1997¹. We now know that obesity leads to decreased life expectancy, poor health and limits quality of life. It also inhibits the overall dynamism of Canadian society and contributes to growing health care costs, and diminished national productivity.

Researchers are looking at both the causes of obesity and its effects on people, with a view to finding new and effective ways to prevent and treat obesity, as well as to minimize the serious health consequences of related diseases such as type 2 diabetes. No single approach or discipline will provide the "magic bullet" for a problem as complex as obesity. As a result, obesity research spans a spectrum that includes pure metabolic research (such as the discovery of the genes and pathways that control energy expenditure), investigations into the cardiovascular and metabolic consequences of increasing or decreasing body weight, and sociological investigations that look at human behaviour in response to community interventions and physical activity programming. New knowledge is needed to develop effective strategies to deal with both the biological and environmental factors driving the pandemic of obesity and its associated health problems.

Obesity - A Pandemic

The prevalence of obesity has increased at an alarming rate over the past two decades, to the extent that it is now a pandemic affecting billions globally². The Canadian experience has been no different than that of many other developed countries. Statistics Canada data demonstrate that more than half of Canadians are overweight or obese, with almost 15 per cent of the population falling in the category of "obese"³. Between 1981 and 1996, the prevalence of obesity in Canada increased from nine to 14 percent in men and from eight to 12 percent in women, while those in the categories of overweight and obesity together increased from 48 to 57 percent among men and from 30 to 35 percent among women. The same research team found similar dramatic trends for Canadian children⁴.

Classifying Obesity

Are you at a healthy body weight, overweight or obese? Internationally, the Body Mass Index (BMI) is one way that doctors and health practitioners make that determination. BMI equals your weight in kilograms divided by your height in meters squared. A BMI between 20 and 25 is considered a healthy body weight. A BMI equal or greater than 25 is considered overweight and equal or more than 30 puts you in the obese category.

Research shows that affected individuals (either overweight or obese), particularly those with high levels of abdominal fat, have an increased risk for type 2 diabetes, hypertension, hyperlipidemia, cardiovascular disease, and cancer. Recent analyses of population data from the United States have shown that obesity and overweight in adulthood are associated with large decreases in life expectancy with increases in early mortality similar to those seen with smoking. There is some good news. Lifestyle modification (i.e. decreases in calorie and fat intake and increased physical activity) leading to even small weight losses in body weight (as little as a five to 10 per cent ) delays or prevents the development of type 2 diabetes⁵.

Obesity - Its Many Causes

Researchers mostly agree that an imbalance between the energy (i.e. food) consumed by an individual and the energy they expend leads to either weight loss or weight gain. However, hundreds of genetic and environmental factors affect how much we eat and how active we are. The challenge today is that the majority of our population consume more energy than they burn, making obesity more and more common.

For example, research involving twins has clearly shown that there are genetic factors at play in the obesity story. Environmental, economic and social forces affect the development of obesity, especially among certain sub-groups of the population. The availability of fast-food products and changing family eating patterns, along with technological developments that decrease the need for physical activity at work and at play, are examples of how external change can affect the individual and their body weight. Researchers are only beginning to unravel the mysteries of this complex condition.

Obesity - Canada's Research Response

In Canada, a significant portion of our nation's obesity research is funded by the Institute of Nutrition, Metabolism and Diabetes (INMD), one of 13 Institutes that comprise the Canadian Institutes of Health Research (CIHR). CIHR is the Government of Canada's funding agency for health research. Working with a wide range of university-based researchers, INMD has put a spotlight on obesity research in recent years.

In 2001, INMD launched a strategic initiative entitled Excellence, Innovation and Advancement in the Study of Obesity and Healthy Body Weight and set aside $3 million in research and training grants per year to fund specific research studies about obesity. Researchers across the country have benefited from these grants and have taken up the research challenge posed by obesity and its varied biological, behavioural and social determinants. Canadian researchers have a growing reputation for the excellence of their studies in the obesity field and their work is well known internationally.

The breadth of programs offered under this strategic initiative signals INMD's intent to continue to build capacity and strengthen Canadian health research in all aspects of obesity/healthy body weight. This research is expected to be in areas from across CIHR's research themes: 1) biomedical, 2) clinical, 3) health systems and services, and 4) the health of populations, including the social, cultural and environmental influences on health. Funding within the initiative is packaged so it can support the creation of multi-disciplinary teams and projects, stimulate innovation, help establish clinical trials and encourage community-based intervention research.

Through this strategic initiative, INMD hopes to challenge scientists working across a host of disciplines to help develop an understanding of the mechanisms (ranging from gene regulation to population behaviour) that will inform the activities of health professionals, policy makers and the Canadian public in the prevention and treatment of obesity and the maintenance of healthy body weight.

Already, INMD has funded projects that examine the correlation between chronic diseases and obesity, cardio-vascular complications associated with obesity, the incidence of diabetes and obesity within aboriginal communities, and the scope of health promotion programs that target healthy weights.

Canada on the Move, funded by INMD and its partners, is an initiative that involves the creation of a national research database about physical activity and pedometer use. Adult Canadians from all parts of the country are being encouraged to monitor their daily movement using pedometers and can submit their personal activity data to a web-based research platform. Authorized researchers will use the data to learn more about what motivates people to be active and if pedometers actually encourage movement.

INMD's focus on obesity has also produced a number of valued partnerships and strategic alliances with other governmental and non-governmental organizations such as the Heart and Stroke Foundation of Canada, the Canadian Diabetes Association, the Kidney Foundation of Canada, Health Canada and many other CIHR Institutes, including the Institutes of Cancer Research, Gender and Health, Musculoskeletal Health and Arthritis, Circulatory and Respiratory Health, Aboriginal People's Health and Human Development and Child and Youth Health.

Ultimately it is INMD's goal to increase our understanding of the measures, causes, prevention, treatment and consequences of obesity and maintenance of body weight. CIHR has a knowledge transfer mandate that will ensure that research findings are shared with the public, health care practitioners and policy makers in ways that make a real difference to the lives of people dealing with the ramifications of overweight or obesity.

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Endnotes:

1) CL Birmingham, JL Muller, A Palepu, JJ Spinelli, and AH Anis. "The cost of obesity in Canada". Canadian Medical Association Journal (CMAJ),160 (1999): 483-8.
2) International Association for the Study of Obesity (IASO) Press Release, (March 17, 2003).
3) MS Tremblay, PT Katzmarzyk and JD Willms. "Temporal trends in overweight and obesity in Canada, 1981-1996". International Journal of Obesity (IJO), 26 (2002):538-43.
4) JD Willms, MS Tremblay and PT Katzmarzyk. "Geographic and demographic variation in the prevalence of overweight Canadian children". Obesity Research. 11 (2003):668-73.
5) WC Knowler et al. "Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin". The New England Journal of Medicine, 346 (6) (2002):393-403.