Understanding obesity as a chronic disease

August 24, 2022

gsc update

Once thought to be simply a result of lifestyle choices, the science has caught up in obesity. Today, it is recognized as a complex, multifactorial, progressive and relapsing chronic disease, characterized by abnormal or excess body fat that impairs health, increases the risk of long-term medical complications, and reduces lifespan.1 In essence, obesity is a disease of energy dysregulation, whereby excess fat tissue can become dysfunctional and predispose individuals to the development of medical complications, including type 2 diabetes, cardiovascular disease, nonalcoholic fatty liver disease, cancer, and more recently, severe COVID-19 disease. For example, it is estimated that 20 per cent of all cancers can be attributed to obesity.2 Furthermore, those living with obesity also experience pervasive weight bias and stigma (leading to inequities in access to employment, health care, and education), which contributes to further increased morbidity and mortality (independent of weight).

Obesity is increasingly becoming a global health issue and is an epidemic in many countries, including Canada. Currently, more than one in four Canadian adults are considered obese, with a higher prevalence among males and those aged 40-69 years.3 In addition to the serious health consequences, obesity has significant economic implications, with an estimated 12 per cent of Canadian health expenditures being attributed to obesity. 4

Despite growing evidence and recognition from the World Health Organization and Canadian Medical Association that obesity is a serious chronic disease, it is not effectively managed within our health care systems (both public and private). First, recognizing obesity as a chronic disease confirms the need to move beyond the traditional approach of “eat less, move more,” and toward evidence-based principles of chronic disease management, not unlike the management of any other chronic disease including type 2 diabetes, high blood pressure, and many others.

Historically, the traditional view of obesity as simply a lifestyle choice shaped the philosophy and approach to coverage of private drug plans – anti-obesity medications have often been excluded from benefit plans or, where coverage is offered, grouped into a “lifestyle drugs” category with arbitrary annual and/or lifetime maximums that often result in inadequate coverage to support appropriate management of the disease.

Today’s anti-obesity medications are not like the “weight-loss drugs” of the past – they are highly effective and safer drugs developed on the new science that considers the multifactorial nature of obesity as a chronic disease.

To align coverage of anti-obesity drugs with the most up-to-date understanding of the disease, GSC has undertaken a comprehensive review of its approach to obesity coverage with a plan to introduce new coverage standards in early 2023. You can expect to read more information in next month’s edition of the GSC Update. Stay tuned.



1 Obesity in adults: a clinical practice guideline. CMAJ 2020. Vol. 192, Issue 31.

2 Obesity and cancer. Oncologist 2010;15: 556-65.

3 CMAJ 2022. DOI:10.9778/cmajo.20210205

4 Cost analyses of obesity in Canada: scope, quality, and implications. Cost Eff Resour Alloc. 2013; 11: 3.