Relationship between BMI with percentage body fat and obesity in Singaporean adults – The Yishun Study.

Background: The main aim of this study was to the determine relationship between Body Mass Index (BMI) and

percentage body fat (BF%) in Singaporean adults, derive a prediction model to estimate BF%, and to report

population BF%. The secondary aim was to determine the prevalence of overweight and obesity based on BF%

threshold and the new risk categories for obesity in Singaporean population.

Methods: This was a population-based study of 542 community-dwelling Singaporeans (21–90 years old, 43.1%

men). Anthropometry and body composition were assessed. Relationship between BMI and BF% were analysed

using multiple regression models. Prevalence of overweight and obesity were estimated using WHO and Singapore

Ministry of Health (MOH) Clinical Practice Guidelines for BMI classification, and BF% cut-off points of 25 and 35% for

men and women respectively.

Results: We derived a prediction model to estimate BF% based on BMI, age and sex. The current cohort of

Singaporeans when compared to Caucasians in the US and Europe as well as a Singapore cohort from 20 years age

have higher BF% when matched for BMI, age, and sex. The overall population-adjusted prevalence of obesity

according to WHO International classification (BMI ≥30 kg/m2) was 12.9% (14.9% men; 11.0% women); and 26.6%

(30.7% men; 22.8% women) according to the MOH classification (BMI ≥27.5 kg/m2). However, using the BF% cut-off

(> 25% for men and > 35% for women) resulted in very high prevalence of obesity of 82.0% (80.2% men; 83.8%

women).

Conclusion: There is a large discrepancy between BF% and BMI measured obesity in Singaporean adults. The

results confirmed that Singaporean adults have higher BF% at lower BMI compared to US and Europe white

counterparts; and that BF% in our population has increased over two decades.