Comparative assessment of methods for determining adiposity and a model for obesity index

Background Obesity is increasingly becoming a pandemic considering the many risks it pose to other disease conditions. Obesity is largely a measure of adiposity, however, adiposity is not centralized in the human body. This makes it difficult for any single method to adequately represent obesity and by extension the risks specific areas of adipose accumulation pose to specific disease conditions. Subjects/Methods We evaluated the prevalence of obesity in a cohort of Ghanaian women using the body mass index (BMI) and further sought to evaluate how it compares to other methods of estimating adiposity and the suitability of any particular methods representing obesity in general. We used anthropometry and bioimpedance derived measures of adiposity and derived other indices such as the abdominal volume index (AVI), body adiposity index (BAI) and conicity index (CI). Results Waist and hip circumference, body fat (%BF) and visceral fat (VF) were positively correlated to BMI whereas skeletal muscle mass was negatively correlated. Physical activity indices did not show any significant correlation with BMI. Prevalence of obesity was 16% and 31% using BMI and %BF respectively. Receiver operating characteristic analysis showed that whereas BMI is effective in predicting underweight, normal weight and obesity it was a poor predictor of overweight. Conclusions There was also no single measure that could adequately predict obesity as an accumulation fat. Hence, we developed and propose a model as a factor of BAI, %BF, VF and BMI. This model should correctly represent a person’s adiposity status and hence should be evaluated in large cohort studies.