BMI is a reliable indicator of total body fat, which is related to the risk of disease and death. Although the score is valid for both men and women, it does have some limitations.

•	It may overestimate body fat in athletes and others who have a muscular build.
•	It may underestimate body fat in older persons and others who have lost muscle mass.

Therefore, determining your waist circumference has become a good indicator of your abdominal fat, which is another predictor of your risk for developing heart disease and other diseases. This risk increases with a waist measurement of over 40 inches in men and over 35 inches in women.

The table below provides you with an idea of whether your BMI together with your waist circumference increases your risk for developing obesity-associated diseases or conditions.

Classification of Overweight and Obesity by BMI, Waist Circumference, and Associated Disease Risks

*Disease Risk Relative to Normal Weight and Waist Circumference**
	BMI (kg/m2)	Obesity Class	Men 102 cm (40 in) or less Women 88 cm (35 in) or less	Men > 102 cm (40 in) Women > 88 cm (35 in)
Underweight	< 18.5		-	-
Normal	18.5 - 24.9		-	-
Overweight	25.0 - 29.9		Increased	High
Obesity	30.0 - 34.9	I	High	Very High
	35.0 - 39.9	II	Very High	Very High
Extreme Obesity	40.0 +	III	Extremely High	Extremely High

*  Disease risk for type 2 diabetes, hypertension, and CVD.
+ Increased waist circumference can also be a marker for increased risk even in
    persons of normal weight.

    Source: NHLBI (National Heart Lung Blood Institute) 2008