Health Topics

What Does My Body Mass Index (BMI) Tell Me About My Health?

The body mass index (BMI) is a tool used to assess and monitor changes in body weight.

Why Worry About BMI?

The body mass index (BMI) is a tool used to assess and monitor changes in body weight. Body mass index is defined as the individual's body mass divided by the square of his or her height, measured in kilograms/meters squared.

To calculate your BMI, divide your weight in kilograms (kg) by height in meters squared (m2).

  • A normal BMI ranges from 18.5 to 24.9.
  • Overweight is defined as having a BMI of 25 to 29.9.
  • A BMI equal or greater than 30 is considered obese.

Your health care provider can also help you calculate your BMI. Doctors often use BMI as an objective indicator of whether a person is overweight, underweight, or at a healthy weight. BMI helps determine someone’s overall health risk and what treatment may be appropriate. It is also used to determine weight loss strategies, including whether weight loss surgery is indicated or not.

Every Body Is Different

BMI has its limitations because it does not measure body fat or muscle directly. Two people can have the same BMI but different body fat percentages. For example, a bodybuilder with large muscle mass and low percentage of body fat may have the same BMI as a person who has more body fat. However, a BMI of 30 or higher usually indicates excess body fat for all people.

Where You Carry Your Weight Matters

How a person’s weight is distributed is also important. People who carry their weight in the middle have a greater risk of developing cardiovascular disease, compared to people who carry their weight in their arms and legs.

  • A man’s waist circumference should be less than 40 inches.
  • A woman’s waist circumference should be less than 35 inches.

The more you weigh, the harder your heart has to work to give your body nutrients. Research has shown that being overweight contributes to the onset of:

  • diabetes
  • heart disease
  • blood cholesterol
  • triglycerides
  • blood pressure

The goal is to have a diet and exercise program that will help you reach your goal weight and maintain a healthy body weight.

Author – Foluke Alli , M.D.