Lack of an association between dietary patterns and adiposity among primary school children in Kilimanjaro Tanzania.

INTRODUCTION: Healthy dietary habits prevent childhood overweight and obesity and the risk of non-communicable diseases (NCDs) later in life. We examined dietary patterns and their association with adiposity among primary school children in northern Tanzania. METHODS: Dietary data was collected by 24-h recall and food frequency questionnaire (FFQ) for 1170 primary school children aged 9 - 11 years from 20 primary schools in the Kilimanjaro region. Factor analysis and FFQ data were used to identify dietary patterns. Children were categorized into terciles of their adherence to each dietary pattern. Multilevel logistic regression was used to evaluate the association of dietary pattern terciles with adiposity indicators: body mass index z-scores (BMI z scores), body fat percentage by bioelectrical impedance, triceps, subscapular skinfold thicknesses, and waist circumference. RESULTS: Fifteen percent of children had BMI Z > 1.0, indicating overweight or obesity. Two dietary patterns were identified by factor analysis: a healthy pattern characterized by frequent consumption of fruits and vegetables; and a mixed dietary pattern characterized by intake of fatty snacks, sweets and sugar snacks, sugary beverages, meat and alternatives, milk, and milk products. After adjusting for potential confounders, for both models: model 1 (age and sex), and model 2 (age, sex, school type, time spent walking to school, district [urban/ rural], availability of television and electronic gadgets at home and neighbourhood playground); we found no significant associations between dietary patterns and adiposity measures. CONCLUSION: Dietary patterns were not associated with adiposity in Tanzanian primary school children, possibly because of limitations of the FFQ, which did not record information on portion sizes. Future research should focus on understanding the key foods / snacks consumed by school children, portion sizes and their long-term effects on adiposity in children.

Prevalence and correlates of overweight and obesity among primary school children in Kilimanjaro, Tanzania.

BACKGROUND: Prevalence of childhood overweight and obesity in low- and middle-income countries is on the rise. We focused on multiple factors which could influence body mass index. METHODS: A cross sectional school-based study was conducted in Moshi, Tanzania. Primary school children aged 9-11 years were recruited from 20 schools through a multistage sampling technique. Questionnaires were used to collect information on physical activity and diet by food frequency questionnaire. Height and weight measurements were taken and body mass index z scores for age and sex (BMIZ) calculated using the WHO AnthroPlus. Children were considered thin if BMIZ was <-2 standard deviations and overweight or obese if BMIZ was >1 SD. Information on school policies and environment was obtained from headteachers. Correlates of overweight and obesity were examined using a multinomial multilevel logistic regression. RESULTS: A total of 1170 primary school children, of whom 636 (54%) were girls, were recruited from 20 schools. The prevalence of overweight and obesity was 15% overall (overweight 9% and obesity 6%) and most prevalent in urban areas (23%) and in private schools (24%). Moreover, thinness was found to be (10%) overall, most prevalent in rural areas (13%) and in government schools (14%). At school level, residing in urban (adjusted relative risk ratio [aRRR] 3.76; 95% confidence interval [CI] 2.49,5.68) and being in private school (aRRR 4.08; 95% CI 2.66,6.25) were associated with a higher risk of overweight and obesity while availability of playgrounds in schools (aRRR 0.68; 95% CI 0.47, 0.97) was associated with a lower risk of overweight and obesity. At home level, availability of sugary drinks (aRRR 1.52; 95% CI 1.01,2.28) was associated with a higher risk of overweight and obesity. CONCLUSION: Overweight and obesity are common in private schools and in urban settings. Efforts should be taken to ensure availability of playgrounds in schools and encouraging children to engage in physical activities.

Description and comparison of physical activity from self-reports and accelerometry among primary school children in Kilimanjaro, Tanzania: a pilot study.

Background: Self-reports are commonly used to assess physical activity in children.  Existing self-reports for physical activity have not been validated for use among primary school children in Kilimanjaro, Tanzania. In order to understand if primary school children can accurately report their physical activity, we examined the validity of self-reported physical activity against accelerometer measured physical activity. Methods: A community based cross-sectional study was conducted from May to July, 2018 among four primary schools in Moshi municipal and Moshi rural districts, Kilimanjaro, Tanzania.  A total of 51 primary school children aged 9-11 years were enrolled using a simple random sampling technique. A self-reported questionnaire was used to collect physical activity related variables. In addition, children wore accelerometers for seven consecutive days to capture physical activity movements. Spearman's rank test and Bland Altman plots were used for assessing validity and agreement between self-reports and accelerometer moderate to vigorous physical activity (MVPA). Results: The mean age of the study participants was 10 (SD=0.8) years. Majority of the study participants were female 32 (63%). A moderate, positive correlation was found between self-reports and accelerometer MVPA (rho=0.36, p=0.009). Accelerometer had higher MVPA compared to self-reports. Children who reported walking to school had higher MVPA for both accelerometer and self- reports compared to children who use other means of transport to school, e.g. school buses (p < 0.001). Conclusions: This study found the moderate positive correlation between self-reports and accelerometers. Self-reports are prone to errors due to recall bias, and this interferes their validity.  More research is needed to develop better self-reported measures with specific activities which can easily be recalled by children. Also, researchers have to be aware of self-reports validity limitation.