Prevalence of overweight and obesity among children and adolescents of affluent schools in Karachi.

OBJECTIVE To estimate the prevalence of overweight and obesity among children and adolescents of affluent schools of Karachi. METHOD This descriptive study is part of an ongoing nationwide project funded by Higher Education Commission (HEC) Pakistan, to develop growth centile charts of our children. This survey of three affluent schools of Karachi was done over a period of three months (from Sept to end Nov, 2007) including 398 children. Socio-economic group was decided based on monthly income and items such as computer, fridge, television, car etc. Students from Class 1-10 representing age group 6 to 17 years were included; children were divided into groups A, B, and C representing age of 6-9, 10-13, and 14-17 years respectively. The children included were healthy with no history of chronic infection and immunization up-to-date as per the Expanded Program of Immunization (EPI) schedule of the country. Body weight was measured in minimum clothing to the nearest 0.1 kg using a weight scale with calibration done after every 25 readings. Body height was measured in the erect position without shoes to the nearest 0.1 cm using wall mounted stadiometers. A twenty four hour diet chart was obtained using specially designed questionnaires. The reference definitions used were those given by the Center for Disease Control (CDC) according to which children having their BMI plotted above 95th centile are obese and BMI between 85th-95th centiles were "at risk for overweight." RESULTS Data of 398 students belonging to affluent schools is presented. Out of these 398, 24 (6%) were above the 95th centile (obese) while 77 (19.35%) were between 85th-95th centiles on NCHS charts (at risk for overweight). The children in group A (6-9 years) showed daily caloric intake of 2220+/-816 kcal/day, group B showed caloric intake of 2133+/-942 kcal/day and group C a caloric intake of 1976+/-873 kcal/day. Apart from the overall data, children above 95th centile and between 85th to 95th centile showed a daily caloric intake of 1861+/-849 and 2056+/-895 kcal per day, respectively. Approximately 85% of the students when asked about their daily schedule were leading a predominantly sedentary life style, due to tuitions, television viewing or internet surfing or indoor games like play stations (not requiring physical activity). CONCLUSION Even with our small sample size the percentage of obese and overweight children were 6% and 19% of the population studied. This study suggests that overweight and obesity among these children maybe due to their sedentary lifestyle and/or lack of intake of proper food (imbalance in the intake of daily calories, carbohydrate, fat and protein).