title: The prevalence of underweight, overweight, obesity and associated risk factors among school-going adolescents in seven African countries.
abstract: BACKGROUND
  The burden caused by the coexistence of obesity and underweight in Low and Middle Income Countries is a challenge to public health. While prevalence of underweight among youth has been well documented in these countries, overweight, obesity and their associated risk factors are not well understood unlike in high income countries.
  
  
  METHODS
  Cross-sectional data from the Global School-based Student Health Survey (GSHS) conducted in seven African countries were used for this study. The survey used a clustered design to obtain a representative sample (n = 23496) from randomly selected schools. 53.6% of the sample was male, and participants ranged in age from 11-17 years old. Body Mass Index (BMI) was calculated using age and sex adjusted self-reported heights and weights. Classification of weight status was based on the 2007 World Health Organization growth charts (BMI-for-age and sex). Multivariable Logistic Regression reporting Odds Ratios was used to assess potential risk factors on BMI, adjusting for age, sex, and country. Statistical analyses were performed with Stata with an alpha of 0.05 and reporting 95% confidence intervals.
  
  
  RESULTS
  Unadjusted rates of being underweight varied from 12.6% (Egypt) to 31.9% (Djibouti), while being overweight ranged from 8.7% (Ghana) to 31.4% (Egypt). Obesity rates ranged from 0.6% (Benin) to 9.3% (Egypt). Females had a higher overweight prevalence for every age group in five of the countries, exceptions being Egypt and Malawi. Overall, being overweight was more prevalent among younger (≤12) adolescents and decreased with age. Males had a higher prevalence of being underweight than females for every country. There was a tendency for the prevalence of being underweight to increase starting in the early teens and decrease between ages 15 and 16. Most of the potential risk factors captured by the GSHS were not significantly associated with weight status.
  
  
  CONCLUSIONS
  The prevalence of both overweight and underweight was relatively high, demonstrating the existence of the double burden of malnutrition among adolescents in developing countries. Several factors were not associated with weight status suggesting the need to explore other potential risk factors for overweight and underweight, including genetic factors and socioeconomic status.
authors.forename: Taru
authors.initials: T
authors.lastname: Manyanga
authors.forename: Hesham
authors.initials: H
authors.lastname: El-Sayed
authors.forename: David Teye
authors.initials: DT
authors.lastname: Doku
authors.affiliation: Department of Community Health Sciences, University of Manitoba, Winnipeg, Canada. Jason_Randall@cpe.umanitoba.ca.
authors.forename: Jason R
authors.initials: JR
authors.lastname: Randall
mesh_terms: D000293:Adolescent; D016497:Adolescent Health Services; D000349:Africa / Q000453:epidemiology; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003906:Developing Countries; D005260:Female; D006306:Health Surveys; D006801:Humans; D016015:Logistic Models; D008297:Male; D009765:Obesity / Q000453:epidemiology*; D016017:Odds Ratio; D050177:Overweight / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors; D012572:School Health Services; D012574:Schools; D012923:Social Class; D013851:Thinness / Q000453:epidemiology; D014944:World Health Organization