British Journal of Nutrition

Human and Clinical Nutrition

Ethnic differences in the relationship between body mass index and percentage body fat among Asian children from different backgrounds

Ailing Liua1a2, Nuala M. Byrnea2, Masaharu Kagawaa3, Guansheng Maa1, Bee Koon Poha4, Mohammad Noor Ismaila4, Kallaya Kijboonchooa5, Lara Nasreddinea6, Trinidad Palad Trinidada7 and Andrew P. Hillsa2 c1

a1 National Institute of Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing, China

a2 Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia

a3 Institute of Nutrition Sciences, Kagawa Nutrition University, Saitama, Japan

a4 Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia

a5 Institute of Nutrition, Mahidol University at Salaya, Nakhon Pathom, Thailand

a6 Department of Nutrition and Food Sciences, Faculty of Agriculture and Food Sciences, American University of Beirut, Beirut, Lebanon

a7 Department of Science and Technology, Food and Nutrition Research Institute, Manila, Philippines


Overweight and obesity in Asian children are increasing at an alarming rate; therefore a better understanding of the relationship between BMI and percentage body fat (%BF) in this population is important. A total of 1039 children aged 8–10 years, encompassing a wide BMI range, were recruited from China, Lebanon, Malaysia, The Philippines and Thailand. Body composition was determined using the 2H dilution technique to quantify total body water and subsequently fat mass, fat-free mass and %BF. Ethnic differences in the BMI–%BF relationship were found; for example, %BF in Filipino boys was approximately 2 % lower than in their Thai and Malay counterparts. In contrast, Thai girls had approximately 2·0 % higher %BF values than in their Chinese, Lebanese, Filipino and Malay counterparts at a given BMI. However, the ethnic difference in the BMI–%BF relationship varied by BMI. Compared with Caucasian children of the same age, Asian children had 3–6 units lower BMI at a given %BF. Approximately one-third of the obese Asian children (%BF above 25 % for boys and above 30 % for girls) in the study were not identified using the WHO classification and more than half using the International Obesity Task Force classification. Use of the Chinese classification increased the sensitivity. Results confirmed the necessity to consider ethnic differences in body composition when developing BMI cut-points and other obesity criteria in Asian children.

(Received September 20 2010)

(Revised January 17 2011)

(Accepted February 16 2011)

(Online publication May 31 2011)


c1 Corresponding author: Professor Andrew P. Hills, fax +61 7 31386030, email


Abbreviations: %BF, percentage body fat; FFM, fat-free mass; IOTF, International Obesity Task Force; TBW, total body water