Trends in body mass index distribution and prevalence of thinness, overweight and obesity in two cohorts of Surinamese South Asian children in the Netherlands

摘要

Objectives: Asians have a smaller muscle mass and a larger fat mass at the same body mass index (BMI) than most other ethnic groups. Due to a resulting higher cardiometabolic risk, the BMI cut-offs for overweight and obesity were lowered for adults. For Asian children universal criteria apply. The Objectives: of this study were to determine the normal BMI distribution and assess the BMI class distribution in a reference cohort of affluent South Asian children born before the obesity epidemic and to assess the influence of the obesity epidemic on the distributions. Methods: Historical cohort study with 4350 measurements of height and weight of two cohorts (born 1974-1976 and 1991-1993) of Surinamese South Asian children living in The Netherlands, analysed with WHO Child Growth References and International Obesity Task Force (IOTF) BMI cut-offs. Results: The reference cohort 1974-1976 was significantly lighter (BMI Z-score=-0.63; 95% CI -0.69 to -0.58) and more variable (SD=1.19) than WHO reference. Total thinness prevalence was exceptionally high, both in cohort 1974-1976 (WHO 38.3%; IOTF 36.4%) and 1991-1993 (WHO 23.6%; IOTF 23.9%). Overweight and obesity prevalences were low in the reference cohort (WHO respectively 6.0% and 2.1%; IOTF 5.3%, 0.9%), but much higher in cohort 1991-1993 (WHO 13.6%, 9.1%; IOTF 11.7%, 6.0%). Conclusions: The low mean BMI Z-score and high prevalence of thinness are likely expressions of the characteristic body composition of South Asians. Universal BMI cut-offs should be applied carefully in South Asian populations as thinness prevalence is likely to be overestimated and obesity underestimated. The development of ethnic specific cut-offs is recommended.