i thought this was really interesting, about waist to hip ratio and BMI:
The global standard for classification of body weight as normal, underweight, overweight or obese is Body Mass Index (BMI). BMI is calculated by dividing a person's weight in kilograms by their height in metres squared. Until recently, the same classification standards have been used in all parts of the world, to assess and categorise body weight: A BMI of 18.5 to 25 is traditionally classified as normal, 25 to 30 as overweight and is associated with increased risk of developing weight-related disorders, and above 30 is classified as obese and at high risk of developing weight-related illness.
In recent years, experts, have observed that weight-related disorders are more common in some Asians ethnic groups at BMI levels above 23. An expert group of the WHO has therefore recommended a lower BMI scale for Asians: 18.5-23 for increasing but relatively low risk of developing weight- related ill-health; 23-27.5 for increased risk; and 27.5 or more signals high risk. (2)
A disadvantage of the BMI scale however, is that it may overestimate body fat in athletes and others, such as Pacific Island ethnic groups, who have a muscular build. BMI may also underestimate body fat in older persons and others who have lost muscle mass. Hence, experts recommend the use of BMI combined with waist circumference or/and waist-to-hip ratio for a more accurate assessment (3).
BMI Formula = Weight in Kilograms
(Height in Meters) x (Height in Meters)
Waist circumference is measured around the narrowest point between ribs and hips when viewed from the front after exhaling. Waist circumference, is a measure of abdominal fat and a good indicator of health status, even when the BMI calculation falls within the range classified as normal. Waist measurements of over 102 cm (40 inches) in men and over 88 cm (35 inches) in women were set as the global thresholds for determining increased likelihood of developing weight-related disorders.
More recently, lower thresholds for waist circumference have been recommended for Asian populations. The Working Group on Obesity in China organized a review of the data on the relationship between BMI, waist circumference and risk factors of related chronic diseases. Based on this review of all the evidence collected to date, the Working Group recommended waist circumferences of over 85 cm for men and over 80 cm for women in China, as the threshold figures for diagnosis of central or abdominal obesity (4). These figures have not been recommended for the whole of Asia but nevertheless, do provide an alternative scale to the global figures which may not fully take into account the differences in fat distribution and body composition between Caucasian and Asians.
Waist-to-Hip Ratio (WHR)
Waist-to-hip ratio (WHR) is the ratio of a person's waist circumference to hip circumference. This measurement can be calculated by dividing waist circumference by hip circumference.
WHR, like waist circumference is a tool to assess distribution of body fat. For most people, and perhaps especially Asian populations, abdominal fat causes more health problems than carrying extra weight around their hips or thighs. A WHR of 0.90 or less is considered healthy for men and a ratio of 0.80 or less is considered a sign of good health for women. A waist : hip ratio of 1 or higher signals increased risk of ill health and an indicator that action to shed some body fat from the tummy would be wise (2)
from http://www.afic.org/FFA%20Issue%2021%20 ... Advice.htm