Utility of BMI and Abdominal Obesity Indices

Globally, the prevalence of overweight and obesity in childhood is increasing. In the Caribbean, at least one in every five children carries unhealthy weight, and risks developing chronic diseases like diabetes in adulthood. In Trinidad and Tobago one in four, one in three, and 25% of school-aged children have been reported to be overweight or obese. This study examined the prevalence of overweight and obesity among 6 to 13 year-old Tobagonian school children utilizing body mass index (BMI) and other abdominal obesity indices, and described the relationships among them. Body weight, height and waist circumference (WC) were measured. BMI, waist-to-height ratio (WHtR), and conicity index (Ci) were calculated. The school children’s (N = 107) ages ranged from six to 13 years. The majority of boys (41.0%) and girls (37.0%) were 11 years old. Mean heights and weights ranged from 132.0±17.8 to 152.0±13.8 cm and 27.8±10.2 to 51.8±17.1 kg, respectively, for all children. The mean BMI ranged from 17.7±3.2 to 21.3±4.7 kg/m2. Girls had slightly higher mean values of WC than boys (70.6±13.4 versus 68±10.8 cm). For both genders, irrespective of age, the mean WHtR values ranged from 0.47±0.1 to 0.49±0.1. Ci values ranged between 1.1±0.2 to 1.2±0.1 for all children. The children’s BMI and WC values were strongly, positively correlated (r = 0.78, P<0.00001), while BMI and WHtR were moderately, positively correlated (r = 0.72, P<0.00001). There was an inverse relationship between BMI and Ci (r = -0.036) and a weak, positive correlation between WC and Ci (r = 0.038). Among the school children, there were 38 and 24% overweight and obesity, respectively, with strong linear relationships among BMI, WC and WHtR. The overweight and obesity seen in Tobago’s primary school children requires introduction of early preventive and management strategies to reduce type 2 diabetes and other chronic disease risks.