Being overweight or obese adds health risks. But how do you know if your weight is in the high-risk zone?

The Canadian Guidelines for Body Weight Classification in Adults is a system used to identify health risks based on two measurements:

This Canadian weight classification system is based on the system recommended by the World Health Organization (WHO). It is important to remember that this classification system is not applicable to people who are:

  • under 18 years old
  • pregnant or lactating

Special consideration should be given when using this system for people with a very lean body build, who are very muscular, and who are over 65 years of age.

The body mass index (BMI)

BMI is not a direct measure of body fat. Rather, it compares your body weight (in kilograms) to your height (in metres). It is the most widely used indicator of health risk associated with being underweight or overweight.

Calculate your BMI to find out what weight and BMI category you fall under.

The table below outlines weight categories according to BMI and associated level of health risks.

Level of health risk associated with BMI categories

Classification BMI category (kg/m²) Risk of developing health problems
Underweight less than 18.5 Increased
Normal weight 18.5 to 24.9 Least
Overweight 25.0 to 29.9 Increased
Obese Class I 30.0 to 34.9 High
Obese Class II 35.0 to 39.9 Very high
Obese Class III over 40.0 Extremely high

Waist circumference

Waist circumference is an indicator of health risk related to excess abdominal (or stomach) fat. Abdominal obesity is associated with much greater health risk than fat found around the hips or elsewhere. According to the Canadian Guidelines for Body Weight Classification in Adults, men with a waist circumference of 102 cm (40 inches) or greater and women with a waist circumference of 88 cm (35 inches) or greater have an increased risk of developing health problems such as type 2 diabetes, heart disease, and hypertension (high blood pressure).

If you have concerns about your BMI or waist circumference, contact your doctor.