BMI & WHR

1. Body Mass Index and Waist Hip
Ratio
By
Dr Utpal Sharma
Assistant Professor
Dept Of Community Medicine
Sikkim Manipal Institute of Medical Sciences

2. Introduction
Body Mass Index (BMI) is the latest tool to assess the
amount of body fatness in a person.
It is a calculation using a person’s height and weight.
Health professionals use BMI to determine if one is
underweight, a healthy weight, overweight or obese.
BMI can provide an indication of weight categories
that could lead to future health problems.
 BMI levels are interpreted differently for adults and
children so different BMI calculators are used.

3. How is BMI used as a Measure of
Health?
BMI is used to screen for weight problems
that may lead to future health problems
For most people BMI is a reliable indicator
of body fatness
The higher the BMI number, the more
body fat a person has.

4. Is BMI always a reliable indicator of
Body Fatness?
Although BMI is a reliable indicator of body
fatness for most people there is an exception:
Athletes: physically fit, may have a high BMI
due to a lot of muscle mass but not due to a
high level of body fatness.

5. How do you calculate BMI for adults
BMI can be calculated using the formula:
 BMI calculator: an easier method is to use a
BMI calculator.
 The adult BMI calculator is used to determine
the BMI for people 20 years of age and over.

6. How to interpret BMI levels for adults?
Classification BMI(kg/m2)
Underweight <18.50
Severe thinness <16.00
Moderate thinness 16.00 - 16.99
Mild thinness 17.00 - 18.49
Normal range 18.50 - 24.99
Overweight ≥25.00
Pre-obese 25.00 - 29.99
Obese ≥30.00
Obese class I 30.00 - 34.99
Obese class II 35.00 - 39.99
Obese class III ≥40.00
Source: Adapted from WHO, 1995, WHO, 2000 and WHO 2004

7. BMI calculation

8. How to interpret BMI levels for children?
For those over 2 years to 20 years of age,
calculating and interpreting BMI levels is
different than for an adult.
The BMI is calculated from the child’s
weight and height, age and sex.
For children and teens, BMI is age- and
sex-specific and is often referred to as BMI-for-
age.

9. Cont….
BMI percentile: a percentile ranking is
also determined.
It is this percentile that is used to evaluate
a child’s weight status.
Like adults, BMI is used to determine if a
child is underweight, a healthy weight,
overweight or obese.

10. The CDC BMI-for-age growth charts

11. BMI Table for Children
Once a BMI percentile is calculated for a child,
then the table below is used:
Weight Status Category Percentile Range
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

12. Waist hip ratio

13. Introduction
The WHR has been used as an
 Indicator or measure of the health of a person, and…..
 Risk of developing serious health conditions
WHR is used as a measurement of obesity….
……which in turn is a possible indicator
of other more serious health conditions.
WHR has been shown to be a better predictor of
cardiovascular disease than waist circumference
and body-mass index

14. Regional Fat Deposition
Abdominal body fat poses greater health
risks than fat stored in other areas
Males store more fat
centrally and have
increased health
risks associated
Male (apple) Female (pear)
with body fatness Higher health risk Lower health risk

15. Types of obesity

16. How to measure WHR?
 According to WHO the waist circumference should be
measured at…..
…….the midpoint between the lower margin of
the last palpable rib and the top of the iliac crest.
 Hip circumference should be measured around…..
………. the widest portion of the buttocks, with
the tape parallel to the floor.
 WHR has been found to be a more efficient predictor of
mortality in older people than waist circumference or BMI

17. Cont….

18. Waist to Hip Ratio (WHR)
Waist to Hip Ratio is an effective way to
examine regional fat distribution.
MEN WOMEN
High Risk
Moderate Risk
Low Risk
> 1.0 > .85
.90 -1.0 .80-.85
HEALTH RISK
< .90 < .80
WHR is not considered to be as valid for
Children…..
People who are under five feet tall or…..
Who have a body mass index (BMI) of 35 or above.