Abstract
Optimal mass (weight) was defined in 2011 as the mass (weight) corresponding to percentile of height. Status of obesity was determined as percentage, by considering optimal mass as reference and could be used in conjunction with body-mass index (BMI) to classify an individual as obese or wasted. This work puts forward a regression model (named as KJ-Regression Model) to evaluate optimal masses of children and adults, whose heights and masses lie below third percentile or above ninety-seventh percentile. For such cases, CDC growth charts, converted into tabular form, cannot be used to determine numerical values of percentiles. Sigmoid function and linear interpolation were used to compute heights and masses corresponding to extreme percentiles (below 3rd or above 97th). In addition to growth curves (plots of height and mass versus age), which include plots corresponding to 0.01th, 0.1th, 1st, 99th , 99.9th and 99.99th percentiles, mathematical formulae are given to compute heights and masses corresponding to any value of percentile (between zero and hundred). Height and mass tables for boys and girls with entries to 5 decimal places, including those corresponding to extreme percentiles, are given in additional files.
