Body Composition Screening and Body Mass Index
Excess fat (not excess weight) is linked with many physical and emotional problems, such as high
blood pressure, heart disease, diabetes, and mental health issues. Body fat can best be measured
by using skin-fold measurement (+/-3% error rate) or by a test called dual energy x-ray
absorptiometry (DXA). Other body fat tests can be affected by many factors and are more prone
to error, so may not give true results.
Another way to assess health is to use body mass index (BMI) and waist circumference.
BMI does not cost much and is easy to do, thus is a useful way to check for weight ranges that
may lead to health problems. BMI does not measure body fat directly, but research has shown that
BMI correlates to direct measures of body fat, such as under-water weighing and DXA.
Adult BMI Chart
Underweight BMI less than 18.5
Healthy Weight BMI greater than 18.5 – 24.9
Overweight BMI 25 – 29.9
Obese BMI 30 – 40
Morbidly Obese BMI greater than 40
Waist circumference is an indicator of your belly fat (or visceral fat), which is related to your risk
for developing heart disease, high blood pressure, and diabetes. Risk increases with a waist
circumference of 40 inches (or greater) in men and 35 inches (or greater) in women.
BMI for Children and Teens
The Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics
(AAP) recommend the use of BMI to screen for overweight and obesity in children starting at 2
years old. After BMI is calculated for children and teens, the BMI number is plotted on the CDC
BMI-for-age growth charts (for either girls or boys) to obtain a percentile ranking. This ranking
is the way most health care providers in the USA use to assess the size and growth patterns of
individual children. The percentile shows the relative position of the child's BMI number among
children of the same sex and age. The chart on page 2 shows the weight status categories used
with children and teens (underweight, healthy weight, overweight, and obese).
Underweight Less than the 5th percentile
Healthy Weight 5th percentile to less than the 85th percentile
Overweight 85th to less than the 95th percentile
Obese Equal to or greater than the 95th percentile
Current Weight __________
Estimated Height __________
Body Mass Index (BMI) __________ Waist Circumference __________
Nutrition goals to achieve a healthy weight:
Exercise goals to achieve a healthy weight:
BMI information and charts obtained from CDC Body Mass Index.
Many insurance providers will cover nutrition counseling for conditions resulting from or related
to obesity. Contact your insurance company to learn whether they will pay for all or some of the
What is the most important thing you learned from this handout?
What changes will you make in your diet/lifestyle, based on what you learned today?
If you are a UW Health patient and have more questions please contact UW Health at one of the
phone numbers listed below. You can also visit our website at www.uwhealth.org/nutrition.
Nutrition clinics for UW Health and American Family Children’s Hospital (AFCH) can be
reached at (608) 890-5500.
Your health care team may have given you this information as part of your care. If so, please use it and call if you
have any questions. If this information was not given to you as part of your care, please check with your doctor. This
is not medical advice. This is not to be used for diagnosis or treatment of any medical condition. Because each
person’s health needs are different, you should talk with your doctor or others on your health care team when using
this information. If you have an emergency, please call 911. Copyright © 2/2017 University of Wisconsin Hospitals
and Clinics Authority. All rights reserved. Produced by the Clinical Nutrition Services Department and the Department
of Nursing. HF#358