Mapping evidence on the burden and distribution of childhood obesity in sub-Saharan Africa: a scoping review protocol
- 175 Downloads
Obesity in childhood is associated with adverse health outcomes and complications throughout the life-span of a child. Available evidence suggests a dramatic increase in childhood obesity in sub-Saharan Africa (SSA) over the past two decades. The health risks associated with obesity/overweight are particularly problematic in children due to the potential for long-term health concerns. The researchers propose to conduct a systematic scoping review to map evidence on the burden and distribution of childhood obesity in SSA.
The study will be guided by the scoping review framework proposed by Arksey and O’Malley. A comprehensive literature search will be performed in the following electronic databases: PubMed, Web of Science, African Index Medicus, and CINAHL with full text via EBSCOhost platform. Primary studies both published in peer-reviewed journals and gray literature such as unpublished studies, thesis, and studies in press addressing the research topic will be included. One reviewer will conduct title screening, and the results will be exported to Mendeley Desktop library. Two independent reviewers will perform both abstract and full article screening in parallel as well as data extraction from eligible studies. The Preferred Reporting Items for Systematic Reviews and Meta-analysis: Extension for Scoping Review (PRISMA-ScR) will be utilized to present the study findings of the proposed scoping review. NVivo version 11.0 will be used to extract the relevant outcomes from the included studies, a content thematic analysis performed, and the results reported using a narrative approach. The Mixed Method Quality Appraisal Tool Version 2018 will be used to assess the methodological quality of all included studies.
We anticipate that the proposed study will contribute to the existing body of knowledge on childhood obesity, identify gaps in knowledge on the topic, inform future research direction, and provide evidence-based information to strengthen health systems and policies on childhood obesity towards achieving the WHO global target of halting the rise in obesity by 2025.
KeywordsPrevalence Incidence Mortality Distribution Childhood Obesity Risk factors Sub-Saharan Africa
Body mass index
Low- and middle-income countries
World Health Organization
Nutritional disorders such as obesity and overweight in childhood and adolescence are associated with adverse health consequences throughout the life-span . The World Health Organization (WHO) defined obesity as abnormal or excessive fat accumulation that presents a risk to health . Obesity results from a complex interplay between genetic, environmental, and socioeconomic factors . Globally, the prevalence of obesity has increased by 27.5% for adults and 47.1% for children . It was estimated that in 2010, overweight/obesity accounted for 3.4 million deaths, 3.9% of years of life lost, and 3.8% of disability-adjusted life-years worldwide . Obesity and overweight were once considered as problems only in high-income countries (HICs) but have now risen dramatically in low- and middle-income countries (LMICs), particularly in urban settings  which sub-Saharan Africa (SSA) is no exception. There has been a dramatic increase in obesity in SSA over the past two decades . In 2013, the worldwide prevalence of obesity among children under 5 years was reported to be 42 million of which LMICs accounted for more than 30% higher prevalence than HICs . It is therefore crucial that children and adolescents are thought basic life skills, including proper nutrition and adequate physical activity to prevent obesity-related health challenges during adulthood .
The WHO classifies obesity as the fifth leading cause of mortality globally and one of the greatest health challenges and determinants for various chronic disease and psychosocial problems . Muthuri et al. assert that the health risks associated with obesity/overweight are particularly problematic in children due to the potential for long-term health concerns . Even though childhood obesity is difficult to diagnose, the body mass index (BMI) percentile charts for age and sex have been widely accepted as the best tool . Body mass index (BMI) is a simple index of weight for height that is commonly used to classify overweight and obesity. It is defined as a person’s weight in kilograms divided by the square of his height in meters (kg/m2) . Researchers have recommended diagnosing a child older than 2 years of age as overweight if the BMI is ≥ 85th percentile but < 95th percentile for age and sex, as obese if the BMI is ≥ 95th percentile, and as extremely obese if the BMI is ≥ 120% of the 95th percentile or ≥ 35 kg/m2 [11, 12].
Obesity is an epidemic which requires novel approaches including preventive, therapeutic, and sociocultural changes which are multidisciplinary in nature to address . Although many studies on obesity in children and adolescents may have been conducted globally, our search in PubMed online database using the following keywords: “epidemiology,” “prevalence,” “obesity,” “overweight,” “child,” “adolescent,” “adolescence,” “sub-saharan africa,” and “scoping review” with no limitations found no study mapping the prevalence of obesity in SSA. Therefore, the proposed scoping review will aim to map evidence on the burden and distribution of childhood obesity (children age between 2 and 15 years) in SSA. It is expected that the results of this study will reveal the current prevalence, incidence, and mortality of childhood obesity in SSA as well as risk factors accounting for the development of obesity in children. We also anticipate that the proposed scoping review will reveal gaps in literature for future research to enable policy decisions and strategies to reduce the burden and also prevent childhood obesity in SSA.
We employed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for protocols (PRISMA-P) to guide this scoping review protocol write-up (Additional file 1). Scoping reviews are important research tools used to map a range of literature that exists around research topics of interest and help to put research questions in perspective by charting existing research findings and identifying research gaps . A scoping study is also considered a useful approach for determining the need and value of future primary studies or a full systematic review . The authors will base this scoping review on the enhanced Arksey and O’Malley scoping review framework which involves the following: identifying the research question; identifying relevant studies, study selection, and charting the data; and collating, summarizing, and reporting results [14, 15].
Identifying the research question
PEO framework for defining the eligibility of the studies for the primary research question
Children (persons aged from 2 to 15 years)
Obesity (children with BMI ≥ 85th percentile)
Risks factors of childhood obesity
What is the evidence on the burden (prevalence, incidence, and mortality) of childhood obesity in SSA?
What is the distribution of the burden of childhood obesity in SSA?
What are the risks factors associated with childhood obesity in SSA?
Identifying relevant studies
Pilot search in PubMed electronic database
31 August 2019
Line 1. “obesity”[MeSH Terms] OR “obesity”[All Fields] OR
Line 2. “obese”[All Fields] OR (“overweight”[MeSH Terms] OR “overweight”[All Fields] OR
Line 3. “body mass index”[MeSH Terms] OR “body”[All Fields] OR
Line 4. “mass”[All Fields] OR “index”[All Fields] OR “body mass index”[All Fields]) OR (bmi [All Fields] AND
Line 5. “child”[MeSH Terms] OR “child”[All Fields] OR
Line 6. “children”[All Fields] OR “childhood”[All Fields] OR
Line 7. “adolescent”[MeSH Terms] OR “adolescent”[All Fields] OR
Line 8. “adolescents”[All Fields] OR “adolescence”[All Fields] OR
Line 9. “youth”[All Fields] OR (“pediatrics”[MeSH Terms] OR
Line 10. “pediatrics”[All Fields] OR “pediatric”[All Fields] OR “pediatric”[All Fields] OR “pediatrics”[All Fields] AND
Line 11. (“africa south of the sahara”[MeSH Terms] OR OR “africa south of the sahara”[All Fields] OR “sub Saharan Africa”[All Fields] OR “sub-Saharan Africa” [All Fields] OR “africa”[MeSH Terms] OR “africa”[All Fields] OR “Angola”[All Fields] OR “Benin”[All Fields] OR “Botswana”[All Fields] OR “Burkina Faso”[All Fields] OR “Burundi”[All Fields] OR “Cameroon”[All Fields] OR “Cape Verde”[All Fields] OR “Central African Republic”[All Fields] OR “Chad”[All Fields] OR “Comoros”[All Fields] OR “Congo”[All Fields] OR “Côte d’Ivoire”[All Fields] OR “Djibouti”[All Fields] OR “Equatorial Guinea”[All Fields] OR “Eritrea”[All Fields] OR “Ethiopia”[All Fields] OR “Gabon”[All Fields] OR “The Gambia”[All Fields] OR “Ghana”[All Fields] OR “Guinea”[All Fields] OR “Guinea-Bissau”[All Fields] OR “Kenya”[All Fields] OR “Lesotho”[All Fields] OR “Liberia”[All Fields] OR “Madagascar”[All Fields] OR “Malawi”[All Fields] OR “Mali”[All Fields] OR “Mauritania”[All Fields] OR “Mauritius”[All Fields] OR “Mozambique”[All Fields] OR “Namibia”[All Fields] OR “Niger”[All Fields] OR “Nigeria”[All Fields] OR “Réunion”[All Fields] OR “Rwanda”[All Fields] OR “Sao Tome and Principe”[All Fields] OR “Senegal”[All Fields] OR “Seychelles”[All Fields] OR “Sierra Leone”[All Fields] OR “Somalia”[All Fields] OR “South Africa”[All Fields] OR “Sudan”[All Fields] OR “Swaziland”[All Fields] OR “Tanzania”[All Fields] OR “Togo”[All Fields] OR “Uganda”[All Fields] OR “Western Sahara”[All Fields] OR “Zambia”[All Fields] OR “Zimbabwe”[All Fields]
Line 12. ((“2009/01/01”[PDAT]: “2019/12/31”[PDAT]) AND
Line 13. “humans”[MeSH Terms])
Eligibility criteria and study selection
To ensure the selection of relevant studies for the proposed scoping review, the study selection will be defined by the eligibility criteria as specified under the inclusion/exclusion criteria.
Evidence of study conducted in sub-Saharan Africa
Studies conducted from 2009 to 2019
Studies focusing on obesity
Studies presenting evidence on children aged from 2 to 15 years
Studies that present evidence on the burden (prevalence, incidence, mortality) of obesity
Studies that present evidence on the distribution (trends) of obesity
Studies that present evidence on risks factors of childhood obesity
Studies reporting evidence in countries not included in the WHO Africa Region
Studies targeting individuals below 2 years and above 15 years
Other types of reviews
Studies focusing on other methods of assessing body composition
Charting the data
Data extraction form
Author and date of publication4
Type of study design
Study setting (country)
Geography setting (rural/urban)
Study population (age and sex)
The data extraction form will include the following information: author with date, study title, study design, country where the study was conducted, population, intervention, outcomes, and other relevant findings.
Collating, summarizing, and reporting the results
The aim of the proposed scoping review is to map the existing evidence on the burden and distribution of childhood obesity, summarize the results as reported in the included studies, and identify gaps for future research. A narrative approach will be used to report the findings from the included studies through thematic content analysis. NVivo version 11.0 software will be employed to extract the relevant themes. The themes will be collated, summarized, and reported around the following outcomes: prevalence, incidence, mortality, trends, and risk factors of childhood obesity. Emerging themes will also be reported.
The Mixed Method Quality Appraisal Tool (MMAT) Version 2018  will be used to assess the methodological quality of all included studies. The MMAT will be used to examine included studies according to the following categories: the appropriateness of the aim of the study, adequacy and methodology, study design, participant recruitment, data collection, data analysis, and presentation of findings. The quality appraisal will enable the reviewers to report on the risk of bias of the included studies and the overall quality of evidence that will be reported.
This proposed scoping review will map evidence of existing literature on the burden and distribution of childhood obesity in SSA. Children between the ages of 2 and 15 years have been identified to have an increased risk of obesity and its related health problems [3, 4, 6], especially in LMICs . The BMI percentile charts for age and sex have been widely accepted as an appropriate and convenient tool for assessing body composition among children [10, 12]. Other studies have also established linkages between obesity and some socio-demographic factors [19, 20, 21, 22]. The researchers, therefore, intend to map literature from 2009 to 2019 to obtain the most recent information on the burden and distribution of childhood obesity in SSA. This study will focus on evidence reported in SSA due to the increasing burden of childhood obesity generally in LMICs [2, 5].
We anticipate that the proposed study will contribute to the existing body of knowledge on childhood obesity, identify gaps in knowledge on the topic, inform future research direction, and provide evidence-based information to strengthen health systems and policies on childhood obesity towards achieving the WHO global target of halting the rise in obesity by 2025 .
The findings of this systematic scoping review will provide evidence that will be beneficial to future research such as systematic reviews, meta-analysis, and primary studies to influence policy and implementation of strategies to end childhood obesity.
We are thankful to the Catholic University College of Ghana, Fiapre, and the University of KwaZulu-Natal, Durban, for providing us with essential research resources to complete this study protocol. We are also grateful to the staff of the Faculty of Health and Allied Science, Catholic University College of Ghana, Fiapre, especially the Dean, for their immense support.
FID and DK conceptualized the study. FID wrote the first draft. MY and DK contributed to the writing of the protocol. VB and DK made the critical revision. FID wrote the final draft, and all authors approved it.
No funding has been obtained for this proposed study yet.
Ethics approval and consent to participate
Consent for publication
The authors declare that they have no competing interests.
- 1.Bentham J, Di Cesare M, Bilano V, Bixby H, Zhou B, Stevens GA, et al. Worldwide trends in body-mass index, underweight, overweight, and obesity from 1975 to 2016: a pooled analysis of 2416 population-based measurement studies in 128·9 million children, adolescents, and adults. Lancet. 2017.Google Scholar
- 2.W.H.O. WHO Media centre Obesity and overweight Fact sheet. 2017;3–7. Available from: http://www.who.int/mediacentre/factsheets/fs311/en/. Accessed 18 May 2019.
- 3.Apovian CM. Obesity: definition, comorbidities, causes, and burden. Am J Manag Care [Internet]. 2016 Jun [cited 2019 mar 18];22(7 Suppl):s176–85. Available from: http://www.ncbi.nlm.nih.gov/pubmed/27356115. Accessed 18 May 2019.
- 4.Ng M, Fleming T, Robinson M, Thomson B, Graetz N, Margono C, et al. Global, regional, and national prevalence of overweight and obesity in children and adults during 1980-2013: a systematic analysis for the global burden of disease study 2013. Lancet. 2014.Google Scholar
- 6.WHO | Obesity. WHO [Internet]. 2014 [cited 2019 Mar 19]; Available from: https://www.who.int/topics/obesity/en/. Accessed 18 May 2019.
- 7.Wyatt SB, Winters KP, Dubbert PM. Overweight and obesity: prevalence, consequences, and causes of a growing public health problem. Am J Med Sci. 2006.Google Scholar
- 8.WHO. Commission on Ending Childhood Obesity [Internet]. WHO. 2016. Available from: http://www.who.int/end-childhood-obesity/en/. Accessed 18 May 2019.
- 9.Muthuri SK, Francis CE, Wachira L-JM, LeBlanc AG, Sampson M, Onywera VO, et al. Evidence of an overweight/obesity transition among school-aged children and youth in sub-Saharan Africa: a systematic review. Dasgupta K, editor. PLoS One [Internet]. 2014 27 [cited 2019 Mar 18];9(3):e92846. Available from: http://dx.plos.org/10.1371/journal.pone.0092846. Accessed 18 May 2019.
- 10.Tyson N, Frank M. Childhood and adolescent obesity definitions as related to BMI, evaluation and management options. Best Pract Res Clin Obstet Gynaecol [Internet]. 2018 Apr [cited 2019 Mar 18];48:158–64. Available from: https://linkinghub.elsevier.com/retrieve/pii/S1521693417301207. Accessed 18 May 2019.
- 11.Styne DM, Arslanian SA, Connor EL, Afrooqi IS, Murad MH, Silverstein JH, et al. Pediatric obesity-assessment, treatment, and prevention: an endocrine society clinical practice guideline. J Clin Endocrinol Metab [Internet]. 2017;102(3):709–57. http://www.embase.com/search/results?subaction=viewrecord&from=export&id=L614843766%5Cn. https://doi.org/10.1210/jc.2016-25730. http://rug.on.worldcat.org/atoztitles/link/?sid=EMBASE&issn=19457197&id=doi:10.1210%2Fjc.2016-2573&atitle=Pediatric+obesity-as. Accessed 18 May 2019.
- 12.Percy R. Primary care management of pediatric obesity; 2017.Google Scholar
- 13.Askey H, O’Malley L. Scoping studies: towards a methodological framework. Int J Soc Res Methodol. 2009.Google Scholar
- 14.Arksey H, Malley LO. Scoping studies: towards a methodological framework 2005;19–32.Google Scholar
- 15.Levac D, Colquhoun H, O’Brien KK. Scoping studies: advancing the methodology. Implement Sci [Internet]. 2010 [cited 2019 mar 23];5(1):69. Available from: http://www.ncbi.nlm.nih.gov/pubmed/20854677. Accessed 18 May 2019.
- 16.Moher D, Liberati A, Tetzlaff J AD. PRISMA 2009 flow diagram. 2009;6:1000097.Google Scholar
- 18.Hong QN, Pluye P, Sergi F, Bartlett G, Boardman F, Cargo M, et al. Mixed methods appraisal tool (MMAT), version 2018. McGill Dep Fam Med [Internet] 2018;1–11. Available from: http://mixedmethodsappraisaltoolpublic.pbworks.com/w/file/fetch/127916259/MMAT_2018_criteria-manual_2018-08-01_ENG.pdf. Accessed 18 May 2019.
- 20.Juwara A, Huang N, Chien L-Y, Chen H-J. Stunting and weight statuses of adolescents differ between public and private schools in urban Gambia. Int J Public Health [Internet]. 2016 Jul 24 [cited 2019 Mar 18];61(6):717–26. Available from: http://link.springer.com/10.1007/s00038-016-0836-6. Accessed 18 May 2019.CrossRefGoogle Scholar
- 21.Omuemu V.O., Omuemu C.E. The prevalence of overweight and its risk factors among adolescents in an Urban City in Edo state. Niger J Clin Pract 2010;13(2):128-33.Google Scholar
- 23.World Health Organization. Global NCD target halt the rise in obesity. 2015;2015–6.Google Scholar
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.