Prevalence and Determinants of Childhood Obesity in Dhaka City

Background: Obesity amongst the children is increasing worldwide at an alarming rate in both developed and developing countries. Obese children are at higher risk of developing coronary heart disease, non-insulin dependent diabetes, respiratory disease etc. Methods: A case-control study, preceded by a cross sectional survey was conducted, aimed to estimate the prevalence rate and to identify the factors associated with the development of childhood obesity in Dhaka city. A multi stage probability proportionate to size (PPS) cluster sampling method was used to obtain the sample. To identify the obese children, a pre-tested questionnaire was used to collect data on age, weight and height among the randomly selected 5000 children of 2-10 years age group from 12 government primary and 23 private elementary schools, 4 hospitals, 8 health centres and 12 immunisation centres (on National Immunisation Days) from all the 12 thanas (civil administrative sub-districts) of Dhaka city. Survey included a medical history and physical examination to assess the eligibility of the subjects for the study. Results: Of 5000 children, 380 (7.6%) were identified as obese using the criterion of weight for height >120% as a cut-off point. Obesity was positively correlated with the increase of age in both sexes (r = 0.76). Of all obese children, 216 (56.8%) were boys and 164 (43.2%) were girls. Prevalence of obesity was significantly higher among the boys than girls (p=0.007). The study was conducted among the 220 cases of 380 obese children (Wt/Ht> 120%) and 220 randomly selected controls, matching age and sex, using a semi-structured questionnaire for identifying the factors associated with the development of childhood obesity. Information also collected from parents of both cases and controls. Family income (p<0.001) and expenditure on food (p<0.001) were significantly higher among the cases. Data showed that parental obesity was significantly associated with the obesity in children. There was an association between obesity of the children and parents’ educational status (p<0.001). There was no difference in the working hours of parents outside households between the cases and controls. Energy balance was significantly higher among the cases. Dose response of energy balance shows, the estimated relative risk of obesity increases with higher levels of energy balance up to a maximum of odds ratio 3.41 (p<0.001). A significant difference (p<0.001) was found in hours of television-video viewing between the cases and controls. Conclusion: Findings of this study show that the obesity among the children is caused by a positive energy balance over a considerable period, is related to environmental factors including energy intake, energy expenditure and other behavioural aspects. Appropriate interventions like behavioural change regarding energy intake and physical activity are thus recommended to address the childhood obesity- an emerging public health problem in Dhaka city. Bangladesh Med Res Counc Bull 2019; 45: 68-80