Samuel's BMI is 40

What is obesity?

Let's start the conversation

Watch the Rethinking Obesity video

Is obesity a disease?

Obesity Canada:

"Obesity is a chronic and often progressive condition not unlike diabetes or hypertension."7

TOS (The Obesity Society):

It is the official position of The Obesity Society that obesity should be declared a disease.8

AACE (American Association of Clinical Endocrinologists):

"[Obesity] must be viewed as a chronic disorder that essentially requires perpetual care, support, and follow-up."9

CMA (Canadian Medical Association):

"It is important for health care providers to recognize obesity as a disease so preventive measures can be put in place..."10

WOF (World Obesity Federation):


The World Obesity Federation takes the position that obesity is a chronic, relapsing, progressive disease process and emphasises the need for immediate action and the prevention and control of this global epidemic.11


Acknowledgement of obesity as a disease could improve the overall management of obesity.12

How have global obesity trends changed?

The global prevalence of obesity has nearly tripled since 1975. In 2016, more than 1.9 billion adults aged ≥18 were overweight. In the same year, 39% of adults aged ≥18 were living with overweight, and 13% were living with obesity.14 


  • Female
  • Male
prevalence of obesity among women, >18, 2016

Obesity is associated with multiple comorbidities.19

The weight of obesity on Canadians

Did you know?

The obesity cycle—Reciprocal link between obstructive sleep apnea and obesity.24

Canadians with obstructive sleep apnea are more likely to have diabetes, hypertension, heart disease and mood disorders.25

The economic weight of obesity in Canada

Conditions associated with obesity have a substantial economic cost.

Obesity was also responsible for high costs associated with its comorbidities 28 

  • Type 2 diabetes: over $1 billion ($746.6 million direct; $306.0 million indirect costs)
  • Hypertension: $877 million ($693.2 million direct; $183.5 million indirect costs)
  • Coronary artery disease: nearly $1.2 billion ($1.02 billion direct; $174.5 million indirect costs)
  • Stroke: $373 million ($305.4 million direct; $67.3 million indirect costs)
  • Chronic back pain: ($1.59 billion indirect costs)

What are the potential benefits of a weight loss of 5–10%?

the benefits of a weight lost of more than 5%

Why is it hard to lose weight and keep it off?

Science has discovered that physiological responses to weight loss trigger weight regain.

Weight loss in people living with obesity has been shown to cause changes in appetite hormones that increase hunger and the desire to eat for at least 1 year.39

Multiple hormones, such as ghrelin, GLP-1, and leptin, play an important role in regulating appetite.2

Want to learn more about the science behind obesity? View our Rethinking Obesity video.

metabolic adaptations to weight loss
Adapted from Sumithran P, et al. (2011); Schwartz A, et al. (2010); Sumithran P, et al. (2013).


The ACTION Study findings

The ACTION (Awareness, Care and Treatment of Obesity MaNagement) Study is the first Canada-wide study that investigated the perceptions, attitudes, and perceived barriers to obesity management among Canadian people living with obesity (PwO), healthcare professionals (HCPs), and employers. The study was conducted through an online survey between August and October of 2017. The findings of this study highlight the misunderstanding and communication gaps that exist between these groups.44

The majority of the 2545 survey respondents* agreed with the statement that “obesity is a chronic medical condition”.44

ACTION study findings

74% of PwO reported that they believe obesity has a large impact on overall health.

81% of PwO agreed that it would be beneficial to their health to lose 5–10% of their body weight.

* PwO (n=2000), HCPs (n=395), employers (n=150).

Selected outcomes of the ACTION Study can be grouped into the following topics:44

How can obesity be treated?

Obesity should be treated and managed holistically and as a serious chronic disease.9,45

Obesity treatment

Behavioural and lifestyle interventions:

For obesity, this should include diet, exercise, and behavioural modification.43 Healthy eating, physical activity, and cognitive behaviour therapy should be first-line interventions in all individuals with a BMI ≥25 kg/m2 and they must be part of any weight loss intervention.19 However, behavioural interventions may not always be sufficient to maintain weight loss and some people living with obesity may require a combination of treatments that includes pharmacotherapy and/or bariatric surgery to help manage their weight.43



For obesity, pharmacotherapy can be considered if lifestyle interventions do not provide sufficient clinical benefit for individuals with a BMI of ≥30 kg/m2, or ≥27 kg/m2 with other comorbidities.19 Pharmacotherapy should be used as an adjunct to lifestyle modifications and considered if a patient has not lost 0.5 kg (1 lb) per week by 3–6 months after lifestyle changes.19


Bariatric surgery:

Is the third-line intervention for obesity management, which is recommended in individuals with a BMI ≥40 kg/m2, or ≥35 kg/m2 with comorbidities.19 Bariatric surgery can be malabsorptive or restrictive and requires lifelong medical monitoring.19,46