Tri-Ponderal Mass Index-A reliable anthropometric index for early screening of adolescent obesity in a school-based setting: A cross-sectional study

Objective: This study was designed to examine the reliability of the Tri-Ponderal Mass Index (TMI) for early screening of adolescent obesity compared with anthropometric measures such as hip circumference, neck circumference, waist circumference, waist-height ratio, waist-hip ratio, and body mass index.

Methods: A school-based, cross-sectional study was conducted between July and December 2019 among 1101 school-going adolescents (both sexes) aged 12 to 17 years, in Rudrapur, Uttarakhand, India. Anthropometric measurements were collected using well-calibrated equipment, and age- and sex-specific BMI percentile cutoff values recommended by the Indian Academy of Pediatrics were used to define overweight and obesity. Statistical analysis was done using SPSS software version 16.0. Receiver operating characteristic curve analysis was conducted, and optimal cutoff values for anthropometric measurements were determined using the Youden Index (sensitivity + specificity - 1).

Results: Of 1101 study participants, 71.5% (n = 787) and 28.5% (n = 314) were males and females, respectively. The prevalences of overweight and obesity were 10.4% and 4.1%, respectively. Receiver operating characteristic curve analysis was conducted and TMI exhibited the highest Youden Index both in terms of overweight (0.835) and obesity (0.869) among adolescents. The optimal TMI cutoff values for overweight and obese males and females were >12 kg/m³ and >14 kg/m³ and >13 kg/m³ and >16 kg/m³, respectively. The TMI demonstrated superior predictive capacity for early screening of adolescent obesity, as indicated by high discriminative power, sensitivity, and specificity.

Conclusions: The TMI can be used as a simple, reliable tool for early screening of overweight and obesity among adolescents.