Body Mass Index
Aim for a Healthy Weight - BMI & Waist Circumference
Body mass index (BMI) and waist circumference are two measurements to identify if you are at increased risk of developing health problems because of your weight. BMI is a simple calculation that measures your weight relative to your height.
Body mass index may not be accurate for those who are:
- Under 18 or not finished growing
- Naturally very lean or very muscular
- Of certain racial and ethnic groups
- Over the age of 65
The BMI score means the following:
| Classification |
BMI Category |
Risk of developing health problems |
| Underweight |
<18.5 |
Increased |
| Normal Weight |
18.5-24.9 |
Least |
| Overweight |
25.0-29.9 |
Increased |
| Obese class I |
30.0-34.9 |
High |
| Obese class II |
35.0-39.9 |
Very high |
| Obese class III |
>40.0 |
Extremely high |
The second measurement is waist circumference. It may be easier to have someone else take your waist measurement. Place the tape measure half way between your hip bone and your lowest rib. This will be about 2 inches above your belly button. Ensure that the tape measure is level all the way around. Take a deep breath, breathe out and measure.
Men with a waist circumference of more than 40 in or 102 cm and women with a waist circumference of more than 35 in or 88 cm are at increased risk of developing health problems such as type 2 diabetes, heart disease and high blood pressure.
Put the two measurements together to determine your overall risk. Even for those with a healthy BMI an elevated waist circumference will indicate an increased risk. Other factors that put you at increased risk are:
- High blood pressure
- High cholesterol
- High triglycerides
- High blood sugar
- Not being physically active
- Cigarette smoking
The risks for each individual needs to take into account other factors such as lifestyle habits, fitness level and the presence of other health conditions. Talk to your doctor if you are at increased risk and need to lose weight. People who are overweight or obese have a greater chance of developing high blood pressure, high cholesterol, type 2 diabetes, stroke and certain types of cancer. Even a small weight loss, just 10% of your current weight will help to lower your risk of developing those diseases.
About the Author
Amy Parker is a Registered Dietitian who regularly writes food and nutrition articles. She graduated from the University of Alberta and completed a one year internship in the Calgary Health Region.
She currently specializes in prenatal nutrition and is passionate about helping her clients have the healthiest babies possible. Her other areas of interest include weight loss, childhood obesity and healthy food that tastes good too!