Prevalence and factors associated with overweight and obesity among primary school children in Kinondoni district, Dar-es-salaam

Abstract

Introduction: Urban Tanzania is currently experiencing nutrition transition- a globalization-related phenomenon that entails the progressive displacement of traditional diets richer in nutrients, in favour of the consumption of unhealthy foods; heavy in added sugar, saturated fat, and sodium and an increase in sedentary life style. Despite these trends little is known about childhood obesity in Tanzania. This study intended to determine prevalence of and factors associated with overweight and obesity among primary school children in Kinondoni district in Dar es Salaam. Methods: This was a cross sectional study of children aged 7-14 years attending primary school in Kinondoni District, Dar es Salaam. Classification of children as overweight or obese was based on the International Obesity Task Force (IOTF) BMI cut off-points for defining overweight and obesity in children between 2 and 18 years. A structured questionnaire was used to collect demographic and risk factor data. Data were analysed using Epi info version 3.5.1. The Chi-squared test was used for categorical data while Logistic regression analysis was conducted to control for confounding. Results: A total of 1722 children aged 7-14 years were recruited. Mean age =10.9 yrs, SD 1.74, mode=12 yrs, median = 11 yrs. A total of 175 (10.2%) were overweight and 78 (4.5%) were obese. Among children who attended public primary schools 49 (4.8%) were overweight while 12 (1.2%) were obese. Among those who attended private primary schools 126 (18.2%) were overweight while 66 (9.5%) were obese. The prevalence of overweight among children attending private schools was found to be statistically significant higher than the prevalence of overweight among children in government schools (95% CI = 0.2 - 0.3, p <0.001). Similarly the prevalence of obesity among children in private schools was found to be statistically significant higher than the prevalence of obesity among children attending government schools (95% CI = 0.1 – 0.2, p<0.001). Children with more than three siblings were less likely to be overweight or obese than those with three siblings or less (OR = 0.69, 95% CI = 0.5- 1.0, p 0.02). Children who walk to and from school were less likely to be overweight or obese than those who use private cars, school transport or public transport (OR =0.46, 95% CI = 0.3-0.6, p <0.001). Among children who reported to commute to school using private cars, school buses or public vii transport those who used private cars or school buses were more likely to be overweight or obese than those who used public transport (OR = 4.17, 95% CI =1.9 - 8.9, p<0.001). Television and computer use were found to be associated with increased risk of overweight and obesity (OR = 1.57, 95% CI = 1.1- 2.3, p0.03). Children who reported to use computers for six hours and less per week were less likely to be overweight or obese than those who reported to use for more than six hours per week (OR = 0.17, 95% CI = 0.1 - 0.3, p <0.001). Eating of breakfast before going to school was found to be protective against overweight and obesity (OR = 0.67, 95% CI =0.5 - 0.9, p 0.01), while children who were given lunch at school were more likely to be overweight or obese than those not given lunch at school (OR=6.36, 95% CI =4.2-9.6, p<0.001). Children who reported to do chores at school (e.g. cleaning of school grounds and classes) were less likely to be overweight or obese than those who reported to not do any chores at school (OR =0.46, 95% CI = 0.2-1.0, p 0.05). Conclusion: This study has demonstrated that a significant proportion of primary school children in Kinondoni district are either overweight or obese. It also shows that overweight and obesity were associated with sedentary life style among children. It is therefore recommended that parents and teachers should sensitize and encourage children to be physically active while at school and at home to avert this problem. Schools / teachers can help children to be physically active by allocating time for sports in school schedules and encouraging children to actively participate.