Forget the Body Mass Index, peeps! It's
inaccurate!
Imagine this... You have four candidates standing in front of
you, they are all 1.7 m tall.
#1 : He's a bodybuilder... his BMI shoots through the
roof! He's supposedly categorised as "morbidly obese"!
#2 : He's a sprinter. He is lean and thin, and according
to his BMI, he is "underweight".
#3 : Has glucose intolerance issues, along with a low metabolic
rate. Needless to say, despite him eating small, healthy
meals, he gets labelled "Obese".
#4 : Extremely skinny guy with a high metabolic rate. He
loves to eat fried and oily food, and doesn't hesitate to consume
animal fat. He is genetically predisposed to have a high
metabolic rate. His BMI is in the 'healthy' range... but is
he really?
Use the Waist-Hip ratio instead. Right now, it is touted
as the most accurate indicator of mortality, as it is a pretty
accurate indicator of cardiovascular health, ie. how healthy your
heart is.
If you are apple-shaped, ie. thick-waisted, your risk of heart
problems increases.
If you are pear-shaped, ie. bottom-heavy, your risk is not as
great.
If you are hour-glass shaped, you risk getting stampeded from
all the lusty and horny chee koh peks! 
Here's what I found from Wikipedia :
"A WHR of 0.7 for women and 0.9 for men have been shown to
correlate strongly with general health and fertility. Women within
the 0.7 range have optimal levels of estrogen and are less
susceptible to major diseases such as diabetes, cardiovascular
disorders and ovarian cancers. Men with WHRs around 0.9, similarly,
have been shown to be more healthy and fertile with less prostate
cancer and testicular cancer.
WHR is a better predictor of mortality in older people than
waist circumference or body mass index (BMI). If obesity is
redefined using WHR instead of BMI, the proportion of people
categorized as at risk of heart attack worldwide increases
threefold.
Other studies have found waist circumference, not WHR, to be a
good indicator of cardiovascular risk factors, body fat
distribution, and hypertension in type 2 diabetes."
Calculate your waist-hip ratio here.