Body Mass Index

Diet and Nutrition


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

How to Calculate Your BMI

Height:  feet inches
Weight: lbs

Your BMI: Switch to Metric Units

The BMI score means the following:

ClassificationBMI CategoryRisk of developing health problems
Normal Weight18.5 - 24.9Least
Overweight25.0 - 29.9Increased
Obese class I30.0 - 34.9High
Obese class II35.0 - 39.9Very high
Obese class III>40.0Extremely 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 ParkerAmy 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!


Further Reading

Body Mass Index - BMI is a simple calculation that measures your weight relative to your height. By Amy Parker, RD

Eating Out - Fast foods and restaurants can be an obstacle to maintaining a healthy weight. Dining out poses many challenges to a healthy lifestyle. By Amy Parker, RD

Goal Setting - With a New Year comes New Year’s Resolutions. By Amy Parker, RD

Healthy Eating - What’s on Your Plate? - In our society a portion sizes have increased to the point where our dinner plates look more like platters.  By Amy Parker, RD

Story on Fat - Low fat, high fat, good fats, bad fats … we are overloaded everyday with information about fat. Fat is an essential element to our diet, we require certain amounts to keep us healthy. By Amy Parker, RD

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