Sitting height ratio and interpretation of BMI-based nutritional status among Sarak adults of Bundu, Ranchi, Jharkhand, India
Sitting height ratio (SHR) affects the rates of nutritional status based on an adjusted body mass index (BMIadj) in adults. Height, weight, and sitting height was measured among 268 adults (158 men) of the Sarak community in Bundu, Ranchi of Jharkhand, India. BMIadj was computed through age-controlled linear regression of SHR on observed BMI (BMIob) by sex. SHR significantly (p< 0.05) predicted BMIob in either sex. BMIob (men 20.3 kg·m-2; women 19.4 kg·m-2) was significantly different (p < 0.05) from BMIadj (men 20.5 kg·m-2; women 19.7 kg·m-2). BMIob-based rates of undernutrition (men 28%; women 46%) and overweight (men 18%; women 12%) have been estimated. BMIadj marginally underestimated the rates of undernutrition (men 27%; women 44%) and overestimated the prevalence of overweight (men 20%; women 13%). However, concordance of the rates (based on BMIob and BMIadj), appraised with Kappa statistics was significantly (p < 0.05) high (men and women 0.9). Adult Saraks were suffering from high degrees of undernutrition, and the situation of women was worse. The modeling of BMIadj based on SHR needs further verification despite high agreement between BMIob and BMIadj in evaluating the rates of nutritional status.