Ethnic-specific body mass index cut-off points for overweight and obesity in girls

To develop ethnic-specific body mass index (BMI) cut-off points for overweight and obesity in girls from New Zealand's five major ethnic groups.

A total of 1676 girls (41% European, 21% Pacific Island, 15% East Asian, 13% Māori, and 11% South Asian) aged 5-16 years participated in this study. BMI was determined from height and weight, and body fat percentage (%BF) was obtained from hand-to-foot bioelectrical impedance measurements. Using stepwise multiple regression, a series of ethnic-specific BMI cut-off points were developed that corresponded to the equivalent %BF of European girls at the BMI reference values provided by the International Obesity TaskForce (IOTF).

The adjusted cut-off points for overweight and obesity ranged from an average of 3.3 and 3.8 kg.m(-2) (respectively) lower than the IOTF standards in South Asian girls to 1.5 and 1.9 kg.m(-2) higher in Pacific Island girls.

We conclude that the ethnic-specific BMI cut-off points developed in this study are more appropriate than universal definitions of overweight and obesity for predicting excess adiposity in New Zealand girls.