Body Mass Index BMI

The Facts on Body Mass Index (BMI)

The Body Mass Index (BMI) is a ratio based on your height and your weight.  It provides a ‘reasonable approximation of adiposity (fatness)’ in a person. BMI is the most common measure used to ‘define’ healthy weight ranges and obesity. 

As BMI increases the predisposition or “risk” of developing chronic health conditions also increases.  Research shows that there is a steady increase in risk of the various diseases (co-morbidities) as weight increases. These diseases include but are not limited to; diabetes, high cholesterol, fatty liver disease, PCOS, high blood pressure, cancer, depression, infertility, osteoarthritis and sleep apnoea etc

 

 

Table 1. Body Mass Index (BMI):

Classification

BMI

Risk of Co-morbidities 

Underweight

Less than 18.5 

Low

(but risk of other clinical problems is increased)

 

Normal Range 

 

18.5 – 24.9

 

Average

 

Overweight

25 – 29.9

Mildly Increased

 

Obese

Greater than 30

INCREASED 

 

  • Obese class 1 

30 -34.99

Modera

  • Obese class 2

35 – 39.99

High

  • Obese class 3

Greater than 40 

Very High