Risk Factors - Body Mass Index

What is BMI?

BMI stands for Body Mass Index. It is a number that shows our body weight adjusted for height, and is calculated with simple math using inches and pounds, or meters and kilograms. 

Why is it important?

It is a way of understanding our weight, and how it fits in a healthy lifestyle.  For adults aged 20 years or older, BMI falls into one of these categories:  Underweight, normal, overweight, or obese.

How does BMI relate to health?

The BMI ranges are based on the effect body weight has on disease and death.  As BMI increases, the risk for some diseases increases.  Some common conditions related to being overweight and obese include:

• Premature death
• Cardiovascular disease
• High blood pressure
• Osteoarthritis
• Diabetes
• Some cancers

BMI is only one of many factors used to predict risk for developing a chronic disease.  Other factors that are important to look at include: 

• Age
• Family history
• Smoking history
• Cholesterol level
• Blood pressure
• Glucose or “sugar” levels
• Diet
• Physical activity

Are athletes and other people with a lot of muscle considered to be overweight when their BMI is over 25?

According to the weight categories, any person with a BMI over 25 would be classified as overweight.  This may not mean they have excess fat.  There is a difference. 

What should I do if I have a higher BMI than I would like?

• All persons who are obese or overweight should try not to gain additional weight.
• In addition, those who are obese or who are overweight with other risk factors should consider losing weight.  Physical activity and good nutrition are key factors in leading a healthy lifestyle and reducing your risk of disease.
• A complete health assessment by a physician is the best way to decide the right steps for you.
• Whatever your BMI, talk to your doctor to see if you are at an increased risk for disease and if you should lose weight. Even a small weight loss (just 10% of your current weight) may help to lower the risk of disease.

Reference: 

Department of Health and Human Services Center for Disease Control and Prevention.  Body mass index: BMI for adults.  Retrieved May 6, 2005, from http://www.cdc.gov/nccdphp/dnpa/bmi-adult.htm.

Simply look at the side for your height.  Then run your finger across horizontally to the box corresponding to your weight.  In that box you’ll see your BMI measure.