Obesity
(Overweight, Unhealthy Weight, Weight Problem)
The Facts on Obesity
Obesity is a leading cause of preventable illness and death in North America. In the last 10 years, the number of overweight people in industrialized countries has increased significantly - so much so that the World Health Organization (WHO) has called obesity an "epidemic." In the United States, 33% of the population - about 60 million people - are overweight. In Canada, about 10% to 25% of teenagers and 20% to 50% of all adults have a weight problem. People who are obese are at a much higher risk for serious medical conditions such as high blood pressure, heart attack, stroke, diabetes, gallbladder disease, and different cancers than people who have a healthy weight.
Causes of Obesity
Obesity occurs when your body consumes more calories than it burns. In the past, many people thought that obesity was simply caused by over-eating and under-exercising, resulting from a lack of will power and self-control. Although these are significant contributing factors, doctors recognize that obesity is a complex medical problem that involves genetic, environmental, behavioural, and social factors. All these factors play a role in determining a person's weight.
Recent research shows that in some cases, certain genetic factors may cause the changes in appetite and fat metabolism that lead to obesity. For a person who is genetically prone to weight gain (e.g., has a lower metabolism) and who leads an inactive and unhealthy lifestyle, the risk of becoming obese is high. Although a person's genetic makeup may contribute to obesity, it's not the primary cause. Environmental and behavioural factors have a greater influence - consuming excess calories from high fat foods and doing little or no daily physical activity over the long run will lead to weight gain. Psychological factors may also foster obesity. Low self-esteem, guilt, emotional stress, or trauma can lead to over-eating as a means to cope with the problem.

Symptoms and Complications of Obesity
The health risks associated with obesity are:
- breathing disorders (e.g., sleep apneal, chronic obstructive pulmonary disease)
- certain types of cancers (e.g., prostate and bowel cancer in men, breast and uterine cancer in women)
- coronary artery (heart) disease
- depression
- diabetes
- gall bladder or liver disease
- high blood pressure
- joint disease (e.g., osteoarthritis)
- stroke
People who are obese may have the symptoms of the medical conditions mentioned above. High blood pressure, high cholesterol levels, breathing problems, and joint pain (in the knees or lower back) are common. The more obese a person is, the more likely they are to have medical problems related to obesity.
Diagnosing Obesity
The diagnosis of obesity is usually based on a physical examination and a patient history (i.e., eating and exercise habits).
A measurement called the body mass index (BMI) does not directly measure body fat, but according to Health Canada, the BMI is the most useful tool to assess the health risk associated with being overweight or obese. A BMI of 18.5 to 24.9 is considered within the healthy range. The BMI is calculated using kilograms (kg) and meters (m), instead of pounds (lb) and inches/feet. Keep in mind that 1 lb equals 0.45 kg and 1 inch equals 0.0254 m.