Body composition derived Body Mass Index and Waist Circumference cut-offs for Sri Lankan adults

Background: Obesity associated non-communicable diseases (NCDs) have emerged as major public health problems in Sri Lanka. However, the absence of derived Body Mass Index and Waist Circumference cut-offs for Sri Lankan adults hinder the early identification of NCDs. The aim of this study therefore was to derive BMI and WC cut-offs for Sri Lankan adults according to body composition data derived from the deuterium dilution technique.

Methods: Demographic and anthropometric measurements were collected from a representative sample of 300 Sri Lankan adults and the deuterium dilution technique was used to estimate fat-free mass (FFM) and fat mass (FM) and subsequently converted to percent body fat. ROC curve analysis was carried out to determine the appropriate cut-offs of BMI and WC at adiposity levels of 25% for men and 35% for women.

Results: A total of 258 participants completed the study; with a mean age of 43.8 (±12.9) years for men and 45.6 (±12.8) years for women, respectively. The majority of participants were Sinhalese from urban residential areas. Mean BMI values were 23.0 kg m⁻² (±4.2) for men and 24.8 kg m⁻² (±4.5) for women. According to our findings, BMI of 23 kg m⁻² corresponds to a body fat percentage of 25% and 35% for Sri Lankan men and women, respectively and body fat percentages of 30% for men and 40% for women equated to a BMI of 25 kg m⁻². Corresponding WC cut-offs for � of 25% and 35% were 85 cm for men and 76 cm for women respectively.

Conclusions: The traditional BMI and WC cut-offs for obesity have grossly underestimated the adiposity status of Sri Lankan adults. Findings from the current study suggest that lower BMI cut-offs be used for the identification of overweight and obesity among Sri Lankan adults.