String Test for Obesity: A Pilot Study

Obesity, particularly central obesity, is the most harmful in terms of various metabolic disorders and conditions. A cutoff of 0.5 for waist-to-height ratio (WHtR) has been suggested as the first level of risk. WHtR is a simple index, potentially a good alternative for central obesity and has enormous practical advantages. The objectives were to develop an innovative tool for central obesity assessment using a string and to explore the incidence of central adiposity among young adults using traditional methods and a string test. This observational pilot study was carried out among young adults aged 18-25 years. Assessment of obesity was done using weight and body mass index (BMI). Assessment of central obesity was done by measuring the waist circumference, hip circumferences, waist-to-hip ratio (WHR) and WHtR. The string test was carried out using a non-stretchable jute twine string. The length of the string was measured from head to toe of the participant and a measured string was folded in half. Using this folded string, the participant’s waist circumference was assessed. The participants were categorized as ‘at risk’ if the folded string was smaller than the waist circumference. Forty (40) young adults (males and females) with a mean age of 21.3±2.26 years participated in this study. The mean WHR of females and males were 0.81±0.074 and 0.74±0.16 respectively. Whereas the mean WHtR among females was 0.50±0.07 and 0.43±0.10 among males. As per WHtR categories, 18(45%) participants were at risk, 2 (5%) were at high risk and the remaining were at no risk. The distance between the two ends of the string showed a significant correlation with WHtR (p<0.01). Similarly, string test observational categories and WHtR categories correlated significantly (p<0.05). The Cronbach alpha analysis of the string test technique was observed to be reliable (α=>0.7). WHtR is a simple anthropometric representation to identify central adiposity. The World Health Organization has stated that WHtR >0.5 is a good predictor of metabolic risk. Thus, this pilot study was an attempt to observe that the string test is a potentially convenient tool for screening central obesity in the Indian community.