Body fat determination by dual energy X-ray absorptiometry and its relation to body mass index and waist circumference in Hong Kong Chinese.
OBJECTIVE
To determine the relationship between percent body fat and body mass index (BMI) in the Chinese population of Hong Kong and to investigate whether the newly proposed lower BMI cut-offs for obesity in the Asia-Pacific Region recommended jointly by the International Association for the Study of Obesity, the International Obesity Task Force and the WHO are appropriate for Hong Kong Chinese.


METHODS
A total of 190 female and 140 male healthy subjects were recruited from the community. BMI was calculated as weight/height(2). Body fat content (%BF) was measured by dual-energy X-ray absorptiometry (DEXA).


RESULTS
Comparing %BF measured by DEXA with predicted %BF derived from BMI using a prediction formula developed in Caucasian population showed that the formula significantly under-predicted %BF by 1.1% in males and 3.4% in females. A predicted BMI of 25 and 30 kg/m(2) using a Caucasian-based formula corresponds to an actual BMI of 23 and 25 kg/m(2), respectively. On linear regression analysis, 25% BF corresponds to a BMI of 24.6 kg/m(2) in males and a waist circumference of 86 cm; 35% BF corresponds to a BMI of 22.6 kg/m(2) and a waist circumference of 73.5 cm in females.


CONCLUSIONS
Hong Kong Chinese population have a higher %BF for a given BMI which would partly explain why the health risks associated with obesity occur at a lower BMI. Our results would support the recommendations of using lower BMI cut-offs to define obesity in the Asia Region.
He
M
M
Department of Medicine, University of Hong Kong, Hong Kong, People's Republic of China.
Tan
K C
KC
Li
E T
ET
Kung
A W
AW
D015502:Absorptiometry, Photon / Q000379:methods*; D000273:Adipose Tissue; D000328:Adult; D000368:Aged; D000886:Anthropometry; D001823:Body Composition; D015992:Body Mass Index; D002681:China / Q000208:ethnology; D005260:Female; D006723:Hong Kong; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000175:diagnosis* / Q000208:ethnology; D044465:White People