Objective: To study the relationship between percent body fat and body mass index (BMI) in two different ethnic groups (Indonesians and Caucasians) in order to evaluate the validity of the BMI cut-off points for obesity. Design: Cross-sectional study. Subjects: Not specially selected populations living in southern Sumatra (Palembang, Indonesia) and Caucasian Dutch living in Wageningen. Measurements: Body weight, body height, body fat by deuterium oxide dilution and skinfold thickness. Results: Body fat could be well predicted by body mass index (BMI) and sex in the Indonesians and by BMI, sex and age in the Dutch with a prediction error of 3.6 and 3.3% for the two populations respectively. Although the body mass index in the Indonesian group was about 2 kgam 2 lower compared to the Dutch, the amount of body fat was 3% points higher. Because of small differences between the groups in age, weight and height the differences in body fat were corrected for this (ANOVA). Indonesians having the same weight, height, age and sex have generally 4.8% points more body fat compared to Dutch. Indonesians having the same % BF, age and sex have generally a 2.9 kgam 2 lower BMI compared to the Dutch. Conclusions:The results show that the relationship between % BF and BMI is different between Indonesians and Dutch Caucasians. If obesity is regarded as an excess of body fat and not as an excess of weight (increased BMI), the cut-off points for obesity in Indonesia based on the BMI should be 27 kgam 2 instead of 30 kgam 2 .

Objective: To study the relationship between body fat percent (BF%) and body mass index (BMI) in two different Indonesian ethnic groups (Malays and Chinese) and to relate differences in the relationship to differences in body build and slenderness. Design: Cross-sectional study. Subjects: Except for ethnicity, not specially selected populations living on Java (Depok, south of Jakarta: Malay Indonesians, n 117) and on Sulawesi (Makale, north of Ujung Pandang: Chinese Indonesians, n 109). Measurements: Weight, height, sitting height, waist and hip circumferences and skeletal widths were measured. BMI was calculated and BF% was predicted from BMI, age and sex using a (Dutch) Caucasian prediction formula. Slenderness was expressed as the ratio of weight : sum of knee and wrist width. BF% assessed by deuterium oxide dilution was used as a reference. Results: BF% in the male and female Malay Indonesians was 24.6 AE 7.0 and 35.6 AE 5.6% respectively which was not signi®cantly different from the values in the male and female Chinese Indonesians (24.0 AE 4.3 and 33.8 AE 6.9%). BMI and age were signi®cantly lower in the Malay Indonesians. Malay Indonesians had a more slender body build in terms of skeletal widths compared to the Chinese Indonesians, and they had a higher slenderness index. BF% predicted from BMI using a Caucasian prediction formula was underestimated by 5.8 AE 4.8% and 7.7 AE 3.8% in the male and female Malay Indonesians but only by 1.3 AE 3.0% and 1.7 AE 3.7% in the male and female Chinese Indonesians. After correction for differences in age, sex and BF% the Malay Indonesians had a 1.7 AE 0.3 kgam 2 (P`0.0001) lower BMI than the Chinese Indonesians. After correcting for body build and relative sitting height the difference lowered to 0.9 AE 0.4 kgam 2 (P`0.02). Conclusions: The study con®rmed the results of an earlier study that Indonesians have a higher BF% at the same BMI compared to Caucasians, but that there are apparently also differences among Indonesian subgroups. These differences are at least partly related to differences in body build.