The Prevalence and Determinants of Undernutrition Among Infants and Children Aged 6 Months to 5 Years in Sub-Saharan African Countries: A Systematic Scoping Review

Abstract

Objective

To explore the prevalence and determinants of undernutrition among infants and children aged 6 months to 5 years in sub-Saharan African countries.

Background

Despite substantial progress over the past 20 years, undernutrition has remained an alarming global challenge. Sub-Saharan Africa is the only region where the prevalence of stunting in children younger than 5 years has significantly increased. This study seeks to update the evidence on the prevalence and determinants of childhood undernutrition in this vulnerable region.

Methods

This systematic scoping review was conducted following the 2018 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews. Five electronic databases were searched on December 14, 2022, with no date or language restrictions. Primary studies presenting evidence on the prevalence and determinants of childhood undernutrition among infants and children aged 6 months to 5 years were included. Data on the prevalence of stunting, wasting, and underweight, and on determinants of undernutrition were extracted, described, and compared with national survey data.

Results

A total of 59 publications from 11 countries were included, with most studies conducted in Ethiopia (n = 38) and Tanzania (n = 7). Stunting prevalence ranged from 8% to 64%, wasting prevalence ranged from 1% to 58%, and the prevalence of underweight ranged from 2% to 63%. The most frequently reported determinants of undernutrition were the child’s age (>24 months), male sex, maternal illiteracy, diarrhea or illness in the past 2 weeks, low household socioeconomic status, or living in a larger household (n > 4 members). Overall, 56% of the included studies reported higher stunting prevalence, 60% reported higher wasting prevalence, and 57% reported a higher prevalence of underweight than reported by relevant national surveys.

Conclusion

The prevalence of childhood undernutrition reported by primary studies is often higher than that reported by national surveys. Several immediate and underlying determinants influence childhood undernutrition. Future research should incorporate the findings from primary research to develop holistic, multistrategy approaches to address childhood undernutrition in sub-Saharan African countries.

INTRODUCTION

Malnutrition is a general term encompassing all forms of undernutrition (ie, stunting, wasting, underweight, and micronutrient deficiencies) and overnutrition (ie, obesity and overweight).^1,2 Undernutrition is the predominant form of malnutrition in developing countries.^3,4 Infants and children aged 6 months to 5 years are most affected by undernutrition due to their vulnerability, physiological needs, and other interacting effects such as growth, development, and nutritional status.^5,6

Childhood undernutrition includes stunting (ie, low height for age or chronic malnutrition), wasting (ie, low weight for height or acute malnutrition), underweight (ie, low weight for age), and micronutrient deficiencies.^1,2 Childhood undernutrition can increase the risk of infectious diseases, diet-related noncommunicable diseases, premature death, and impaired physical and cognitive development.⁴ It can also adversely affect the economic productivity of countries and increase healthcare costs.^7–9 The prevalence of childhood undernutrition is highest in 49 of 54 African countries classified as Sub-Saharan Africa (SSA),¹⁰ with very little progress—and even regression—over the past decade, particularly in the prevalence of stunting.¹¹

Childhood undernutrition has been a major focus of international research for decades and has gained rapid traction in global public health research.^7,12 Over the past two decades, there has been modest progress in reducing the prevalence of stunting or chronic malnutrition from 32.4% to 22.3% globally.¹³ The number of countries with very high stunting prevalence has declined by 40% since 2012, from 46 to 28 countries.¹³ However, progress and efforts in reducing stunting have been characterized by substantial inequalities due to location, age, sex, education, and wealth; and conflict and other forms of fragility escalate the problem across regions and sub-regions.^14–17 As a result, the prevalence of stunting in SSA countries has remained unacceptably high,¹⁸ with the number of children with stunting increasing from 54.4 million in 2000 to 61.4 million in 2020.¹⁹ A recent report by the United Nations Children's Fund (UNICEF) noted that in 2022, 31.5% of the population in SSA countries were moderately or severely stunted, and 6.0% of the population experienced moderate to severe wasting.¹³

Despite improvements in selected nutritional indicators of stunting, wasting, and underweight in infants and children younger than 5 years, progress is insufficient to meet the 2025 World Health Assembly global nutrition targets and the related Sustainable Development Goals by 2030.^20,21 According to the 2022 Global Nutrition Report, progress toward the global nutrition targets in Africa has been modest, with only 6 countries on course to meet the target for stunting in infants and children younger than 5 years, and 19 countries on course to meet the target for wasting in this age group.²² Concerningly, 8 SSA countries (ie, Angola, Burundi, Central African Republic, Djibouti, Eritrea, Mauritius, Niger, and South Africa) showed either no progress or worsening in stunting, whereas 9 SSA countries (ie, Benin, Republic of the Congo, Guinea, Guinea-Bissau, Mali, Mauritania, Sudan, Senegal, and Togo) showed either no progress or worsening in wasting in infants and children younger than 5 years.²²

Malnutrition research often uses population-based survey data for advocacy, strategy or program development, monitoring, and evaluation.²³ Country-level survey data sets have been essential sources of information on child health and nutritional status in developing countries for many years.²⁴ However, there has been growing concern within the literature that these country-level survey data sets have limitations, including a lack of granular data on nutritional outcomes, as well as strategies that rely on biased information for sampling and limit how much data can be disaggregated.²⁵ Additionally, obtaining anthropometric measures in large-scale surveys is complex and challenging, with errors in anthropometric measures being commonplace and difficult to isolate.²⁶ Moreover, data collection occurs every 3 to 5 years in most countries, assessing nutrition status at one time point, resulting in sparse data for most SSA countries.²⁷ Finally, it is unlikely that household surveys and anthropometric data were collected during the COVID-19 pandemic, due to travel restrictions, lockdowns, and social distancing policies, which may have resulted in significant data gaps.

Childhood undernutrition is influenced by a complex interplay of intra- and intergenerational factors.²⁸ Several previous reviews focused on childhood undernutrition in SSA countries.^2,27,29,30 Akombi et al, conducted a systematic review, published in 2017,²⁹ to determine the factors associated with stunting, wasting, and underweight in children younger than 5 years in SSA countries, including 49 studies published between 1992 and 2017. A narrative review by Quamme and Iversen²⁷ provided evidence from 13 studies published between 2000 to 2020 to assess the prevalence and risk factors of stunting in children younger than 5 years in SSA countries. Finally, two scoping reviews aimed to identify the risk factors associated with malnutrition in children younger than 5 years in SSA—one by Obasohan et al,² published in 2020, which included 26 studies; and one by Simwanza et al,³⁰ published in 2022, which only included 8 studies. These reviews had various limitations, including searches restricted to particular databases, dates, and/or English-only publications; the exclusion of potentially important studies; and a focus on national data sets, resulting in the evidence on the determinants of childhood undernutrition at individual, household and community levels remaining unclear.

In the present systematic scoping review, we aimed to provide a comprehensive update to the evidence on the prevalence and determinants of undernutrition among infants and children aged 6 months to 5 years in SSA countries by including peer-reviewed studies reporting primary research and comparing the findings with national health survey data.

METHODS

Protocol and Registration

The protocol for this systematic scoping review was registered on December 26, 2022, in the Open Science Framework and can be accessed at https://doi.org/10.17605/OSF.IO/7ER5Q. A scoping review methodology was selected because it provides a broad overview of the subject and enables the synthesis of findings across various study designs.^31,32 The study followed an improved Arksey and O'Malley methodological framework,³¹ and the 2020 Joanna Briggs Institute (JBI) Manual for Evidence Synthesis.³² The methods involved 5 stages: (1) identifying the research question, (2) identifying relevant studies, (3) study selection, (4) charting the data, and (5) collating, summarizing, and reporting the results.³¹ The systematic scoping review results are reported in full and presented using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) flow diagram.³³

Search Strategy

A systematic literature search was performed to retrieve publications on the prevalence and determinants of undernutrition among infants and children 6 months to 5 years in SSA countries (Table S1). The search was completed in three parts. First, a preliminary search of the MEDLINE (PubMed) database was completed to identify relevant studies and gather key words and Medical Subject Heading (MeSH) terms. These terms and keywords were combined to develop a search strategy designed for MEDLINE (PubMed), which was translated using the Systematic Review Accelerator Polyglot (https://sr-accelerator.com/#/polyglot). Second, 5 electronic databases were searched: MEDLINE (PubMed), Embase (Elsevier), CINAHL (EBSCO), ProQuest, and SCOPUS (Elsevier) from commencement to December 14, 2022. No language or date restrictions were applied. Finally, forward and backward citation searching of included studies and previous reviews was completed to identify additional studies.

Eligibility Criteria

The Population-Concept-Context framework proposed in the 2020 JBI Manual for Evidence Synthesis was used to develop the inclusion and exclusion criteria (Table 1).^10,32,34,35 Arksey and O’Malley suggested the scoping review study method should identify all relevant literature regardless of the study design.³¹ This systematic scoping review included all peer-reviewed primary studies that met the eligibility criteria, such as cohort studies, case-control studies, and cross-sectional studies. We excluded abstract-only publications, books, theses, case series, opinion pieces, government and not-for-profit reports, protocols, systematic reviews, unpublished studies (grey literature), and publicly available data sets.

Table 1.

Population-Concept-Context Criteria for Inclusion and Exclusion of Studies^a

Parameter	Determinant	Inclusion Criterion	Exclusion Criterion
Participants	Infants and children (aged 6 mo to 5 y)	Studies presenting evidence on infants and children aged 6 mo to 5 y	Studies presenting evidence on infants aged <6 mo or children >5 y, adolescents, or adults, unless data for infants and children aged 6 mo to 5 y were reported separately Studies reporting on undernutrition in infants and children with specific physical and cognitive impairments
Concept	Prevalence and determinants of childhood undernutrition	Studies presenting evidence on the prevalence and determinants of undernutrition among infants and children aged 6 mo to 5 y	Studies that do not report on the prevalence and/or determinants of childhood undernutrition
Context	Sub-Saharan Africa refers to 49 of 54 African countries (Table S2)	All studies reporting evidence from sub-Saharan countries	All studies reporting evidence from outside sub-Saharan African countries (ie, North African countries and nonself-governing territories)
Source of evidence	Study design	Primary studies and publications, including quantitative, qualitative, and mixed methods studies	Case studies, abstract-only publications, books, theses, case series, nonresearch opinion pieces, government and not-for-profit reports, protocols, and systematic reviews

^aAdapted from the Population-Concept-Context framework proposed in the Joanna Briggs Institute Manual for Evidence Synthesis.³²

Primary studies presenting evidence on the prevalence and determinants of childhood undernutrition in infants or toddlers (ie, aged 6 months to 2 years) and children or preschoolers (ie, aged 3 to 5 years) were included.³⁴ We excluded studies that reported data on infants younger than 6 months, children older than 5 years (ie, aged 5 to 10 years), adolescents (aged 10 to 18 years), or adults unless data on the target population (ie, infants and children aged 6 months to 5 years) were reported separately. Additionally, studies that included infants and children aged 6 months to 5 years with specific physical and cognitive impairments, such as developmental delays or any growth retardation and illness other than childhood undernutrition, were excluded. This study included publications reporting evidence from the 49 SSA countries defined by the World Bank Group (Table S2).¹⁰

Study Selection and Data Extraction

All identified records were imported into reference manager software (EndNote), and deduplicated.³⁶ The remaining citations were screened using Covidence systematic review software.³⁷ Title and abstract screening were conducted by two independent reviewers (F.P.R. and M.A.J.), and disagreements were resolved through discussion with a third party (K.O.J.). Two reviewers completed the full-text screening independently (F.P.R. and K.O.J.), with conflicts resolved through discussion with a third reviewer (M.A.J.). Two reviewers (F.P.R. and K.O.J.) developed a standardized data extraction form, piloted the data extraction form with 5 studies, and revised the form after this pilot. The first reviewer (F.P.R.) independently extracted data from all studies, and the second and third reviewers (M.A.J. and K.O.J.) checked all extracted data.

Data Analysis

Three reviewers (F.P.R., M.A.J., and K.O.J.) completed data analysis, and all reviewers contributed to data interpretation.

Prevalence data were organized by country, summarized, and classified according to the prevalence thresholds of stunting and wasting from the World Health Organization (WHO) and UNICEF.³⁸ These data were compared with national survey data from the relevant country to the closest year and categorized as higher, lower, or the same as the national level data. According to the WHO–UNICEF prevalence thresholds, stunting prevalence of ≥30% is classified as “very high” and indicates a critical need for intervention.³⁸ The prevalence of wasting of ≥15% is classified as “very high” and requires urgent intervention.³⁸ Underweight is a composite index of stunting and wasting measures and, therefore, has no prevalence thresholds.

Data on the determinants of childhood undernutrition identified by the individual studies as being statistically significant (P < .05) through logistic regression analysis were extracted and summarized. The determinants of childhood undernutrition most commonly reported as significant by the included studies were organized into overarching categories using the preselected 2020 UNICEF conceptual framework on maternal and child nutrition.³⁹ This framework provides conceptual clarity on the determinants of malnutrition to prevent malnutrition for mothers and children.³⁹ The determinants were classified as child-related, household-related, and maternal-related factors that fit within the overarching diets and care (immediate determinants) and food, practices, and services (underlying determinants) categories defined by the UNICEF conceptual framework.^39–41 All reviewers independently reviewed the data, met to discuss the results, and agreed upon the final themes.

Changes from the Registered Protocol

We initially planned to include systematic reviews in the study; however, upon reviewing the included studies, we noted significant overlap. Instead, we refer to these systematic reviews in the “Discussion.”

RESULTS

The search identified 5842 records, and 18 additional records were identified through citation searching. After removing duplicates, 2237 records were screened against the selection criteria, and 133 full-text studies were assessed (Figure 1). A total of 59 studies were included. All included studies were published in English. The complete list of included studies is provided in Table 2.^1,42–119

Figure 1.

PRISMA Flow Diagram

Table 2.

Summary of Studies (n = 59) that Reported Prevalence of Stunting, Wasting, and Underweight Among Infants and Children Aged 6 Months to 5 Years by Sub-Saharan African Country^a

Author (Year)	Data collection period	Age of participants (no.)	Prevalence of stunting	Prevalence of wasting	Prevalence of underweight	Prevalence reported in national surveys
CAMEROON
Manjong et al (2021)75	August–September 2019	0–59 mo (468) (Data included for ages 6–59 mo only; 437)	58% (6–12 mo); 58.2% (12–23 mo); 46.6% (24–48 mo); 58.2% (48–59 mo) 55.08% (34.53% severely stunted) ↑	12.7% (6–12 mo); 14.8% (12–23 mo); 9.1% (24–48 mo); 19.5% (48–59 mo) 13.77% (3.18% severely wasted) ↑	30.9% (6–12 mo); 27.2% (12–23 mo); 32.7% (24–48 mo); 19.5% (48–59 mo) 31.99% (10.59% severely underweight) ↑	CDHS 2018 Stunting, 29%; wasting, 4%; and underweight 11% INS and ICF (2020)100
Ngassa et al (2022)81	March and June 2021	6–59 mo (321)	26.5%↓	3.7% ↓	1.6% ↓
ETHIOPIA
Haidar et al (2005)68	February 2003	6–59 mo (200)	44.5%↓	9.0%↓	25.0%↓	EDHS 2005 Stunting, 47% (severe stunting, 24%) Wasting, 11% (severe wasting, 2%) Underweight, 38% (severely underweight, 11%) CSAE (2005)101
Egata et al (2013)58	July 2010–February 2011	6–36 mo (2132)	NR	7.4% (wet season) ↓ 11.2% (dry season) ↑	NR	EDHS 2011 Stunting, 44%; wasting, 10%; underweight 29% CSAE and ICF (2012)102
Darsene et al (2017)54	August–September 2012	6–59 mo (811)	39.3% (12.1% severely stunted) ↓	6.3% (2.3% severely wasted) ↓	15.7% (4.2% severely underweight) ↓
Alemayehu et al (2015)46	September 2013	6–59 mo (601)	56.6%↑	34.6%↑	45.3%↑	Mini-EDHS 2014 Stunting, 40%; wasting, 9%; underweight 25% CSAE (2014)103
Asfaw et al (2015)49	February–March 2013	6–59 mo (778)	47.6% (20.2% severely stunted) ↑	13.4% (3.9% severely wasted) ↑	29.1% (6% severely underweight) ↑
Fentahun et al (2016)62	April–May 2014	6–59 mo (633)	57.7%↑	16%↑	NR
Abebe et al (2017)42	October 2013–November 2014	6–59 mo (707)	45.7% (21.2% severely stunted) ↑	6.5%↓	NR
Eshete et al (2017)60	January 2014	6–59 mo (315)	18.4%↓	29.9%↑	29.9%↑
Demilew and Abie (2017)55	May 2015	24–36 mo (471)	42% (16.3% severely stunted) ↑	6.4% (1.3% severely wasted) ↓	22.1% (3.8% severely underweight) ↓	EDHS 2016 Stunting, 38% (severe stunting, 18%); wasting, 10% (severe wasting, 3%); underweight, 24% (severely underweight, 7%) CSAE (2016)104
Derso et al (2017)57	May–June 2015	6–24 mo (587)	58.1%↑	17.0%↑	NR
Workie et al (2020)97	May–June 2015	12–59 mo (595)	34.1% (15.6% severely stunted) ↓	6.9% (3% severely wasted) ↓	11.9% (4.1% severely underweight) ↓
Abera et al (2017)43	February–March 2016	6–59 mo (398)	NR	9% ↓	27.6%↑
Kassa et al (2017)71	April–May 2016	6–59 mo (384)	38.3%	25.5%↑	49.2%↑
Tosheno et al (2017)95	February–April 2016	6–59 mo (642)	NR	NR	24.6% (5% severely underweight) ↑
Girma et al (2019)66	January–February 2017	24–59 mo (401)	28.4%↓	10%	13.4%↓
Engidaye et al (2022)59	January–May 2017	6–59 mo (432)	50.2%↑	11.3%↑	28%↑
Abeway et al (2018)44	February–March 2017	6–59 mo (410)	52.4% (18% severely stunted) ↑	NR	NR
Gebre et al (2019)64	March 2017	6–59 mo (840)	24.8% (16.7% severely stunted) ↓	16.2% (5.7% severely wasted) ↑	43.1% (13.1% severely underweight) ↑
Tesfaye and Egata (2022)94	March 2017	6–59 mo (1555)	40.6%↑	NR	NR
Gelu et al (2018)65	May 2017	6–59 mo (593)	42.3% (15.9% severely stunted) ↑	7.3% (2.4% severely wasted) ↓	NR
Tufa et al (2018)96	May–June 2017	6–59 mo (342)	NR	11.1% (4.4% severely wasted) ↑	14% (3% severely underweight) ↓
Demilew and Alem (2019)56	June 2017	6–59 mo (815)	40% (13.5% severely stunted) ↑	11.6% (4.2% severely wasted) ↑	19.8% (4.8% severely underweight) ↓
Feleke et al (2021)61	January–March 2018	6–59 mo (410)	12.2% (4.9% severely stunted) ↓	37.8% (5.1% severely wasted) ↑	21.7% (3.9% severely underweight) ↑	Mini-EDHS 2019 Stunting, 37%; wasting, 7%; underweight, 21% EPHI and ICF (2021)105
Tafesse et al (2021)92,b	January–March 2018	6–59 mo (237) (n = 79 cases, n = 158 controls)	33.3%↓	NR	NR
Melese et al (2020)76	March–April 2018	36–59 mo (408)	21.8%↓	17.2%↑	15.2%↓
Habtamu et al (2022)67,b	May–July 2018	6–59 mo (356) (n = 199 cases, n = 237 controls)	NR	33.4%↑	NR
Berr et al (2021)51	March 2019	6–59 mo (575)	35.1%↓	4.7%↓	12%↓
Teferi and Teshome (2021)93	July–August 2019	6–59 mo (227)	34.8%↓	4.4%↓	12.3%↓
Roba et al (2021)86	June–September 2019	6–59 mo (1091)	53.9% (36.9% severely stunted) ↑	16.8% (5.2% severely wasted) ↑	36.9% (21.9% severely underweight) ↑
Menalu et al (2021)1	October 2019–January 2020	0–59 mo (385) (Data included for 6–59 mo only; n = 147)	10.9% ↓	NR	6%↓
Anato (2022)48	February–March 2020	6–59 mo (384)	NR	12.8% (5.8% severely wasted) ↑	NR
Sewnet et al (2021)90	February–March 2020	6–59 mo (271)	45.8%↑	11.1% ↑	25.5%↑
Tafese et al (2022)91	March–May 2020	6–23 mo (354)	42.7%↑	9.9% ↑	27.7% ↑
Ketema et al (2022)73	April 2020	6–23 mo (597)	35.5%↓	16.9%↑	31.8% ↑
Fufa and Laloto (2021)63	April–May 2020	6–36 mo (700)	48.9% ↑	6.7%↓	22.6% ↑
Yazew (2022)98	December 2020	6–59 mo (500)	27%↓	11.8%↑	NR
Yeshaneh et al (2022)99	December 2020–January 2021	6–59 mo (293)	NR	14.7% (3.4% severely wasted) ↑	NR
Sewenet et al (2022)89	October–November 2021	6–23 mo (421)	36.8%↓	11.5%↑	27.6%↑
GHANA
Bandoh et al (2018)50	March–April 2015	6–59 mo (250)	17.6%↓	4.4%↓	12%↑	GDHS 2014 Stunting, 19%; wasting, 5%; underweight, 11% GSS (2015)106
Ali et al (2017)47	2016	6–59 mo (425)	28.2%↑	9.9%↑	19.3%↑
KENYA
Bloss et al (2004)52	July–August 2002	0–60 mo (154 (Data included for 13–59 mo only; n = 115)	51.3%↑	NR	28.7%↑	KDHS 2003 Stunting, 30% (severely stunted, 11%), Wasting, 6% (severe wasting, 1%), underweight 20% (severely underweight, 4%) CBS (2004)107
Olack et al (2011)85	March–April 2008	6–59 mo (1245)	47% (23.4% severely stunted) ↑	2.6% (0.6% severely wasted) ↓	11.8% (3.1% severely underweight) ↓	KDHS 2008–2009 Stunting, 35% (severe stunting, 14%) Wasting, 7% (severe wasting 2%) Underweight, 16% (severely underweight, 4%) KNBS and ICF (2010)108
MOZAMBIQUE
Rose et al (2015)87	Baseline (August and September 2010) and endline (April and May 2014)	6–59 mo (560)	2010: 39% ↓ 2014: 51% ↑	2010: 7% ↑ 2014: 5% ↑	13% (2010 and 2014) ↓	MDHS 2011 Stunting, 43% (severe stunting 20%) Wasting, 1.7% (severe wasting 2%) Underweight, 15% (severely underweight, 4.1%) MISAU et al (2011)109
NIGERIA
Odunayo et al (2006)83,c	NR	12–59 mo (420)	26.7% ↓	9% ↓	23.1%	NDHS 2008 Stunting, 41% (severe stunting, 23%); wasting, 14% (severe wasting, 7%), underweight, 23% (severely underweight, 9%) NPC and ICF (2009)110
Dada et al (2021)53,c	NR	0–59 mo (531) (Data included for 13–59 mo only; n = 181)	27.9%↓	6.7%↓	12.2% ↓	NDHS 2018 Stunting, 37% (severe stunting, 17%) Wasting, 7% (severe wasting, 2%) Underweight, 22% (severely underweight, 7%) NPC and ICF (2019)111
RWANDA
Mutsindashyaka et al (2020)80	April 2014–September 2017	6–59 mo (641)	58.8%↑	25.8% ↑	47.5% ↑	RDHS 2014–2015 Stunting, 38% (severe stunting 14%) Wasting 2% (severe wasting, 0.6%) Underweight 9% (severely underweight, 2%) NISR et al (2015)112
SOUTH AFRICA
Schoeman et al (2010)88	2003	0–71 mo (994) EC; n = 992 KZN (Data included for 6–59 mo only; n = 674 EC; n = 704 KZN)	(EC: 22%; KZN: 24%) ↓	(EC: 5%; KZN: 4%) ↓	EC: 11%↓ KZN: 12%	SDHS 2003 Stunting 27%, wasting 5%, underweight 12% DOH et al (2007)113
SOUTH SUDAN
Kiarie et al (2021)74	October–November 2018	6–59 mo (630)	23.8%↑	2.3%↓	4.8%	FSNMS 2018 Stunting, 17.1%; wasting, 13.3% WFP et al (2018)114
UGANDA
Kasajja et al (2022)70	November 2014	6–59 mo (640)	41.1%↑	1.3%↓	7.7% ↓	UDHS 2016 Stunting, 29%; wasting, 4%; underweight, 11% UBOS and ICF (2018)115
Okidi et al (2022)84	October–December 2019	6–59 mo (240)	AZ: 48.3% APZ: 44.8%; PZ: 58.2% ↑	AZ: 43.8%; APZ: 52.1%; PZ: 58.2% ↑	AZ: 46.1%; APZ: 49%; PZ: 56.4% ↑
UNITED REPUBLIC OF TANZANIA
Nyaruhucha et al (2006)82	2005	0–59 mo (250) (Data included for 12–59 mo only; n = 184)	NR	NR	29.9% (6% severely underweight) ↑	TDHS 2004–2005 Stunting, 38% (severe stunting, 13%) Wasting, 3% (severe wasting, 0.4%) Underweight, 22% (severely underweight, 4%) NBS and ORC (2005)116
Juma et al (2016)69	January–December 2009	6–59 mo (63 276)	8.4% ↓	1.4%↓	5.7% ↓	TDHS 2010 Stunting, 42% (severe stunting, 17%) Wasting, 5% (severe wasting, 1%) Underweight, 16% (severely underweight 4%) NBS and ICF (2011)117
Mgongo et al (2017)77	June 2010–March 2011	7–24 mo (7–12 mo [649]) (13-24 mo [739])	34.7% (7–12 mo); ↓ 56.0% (13–24 mo) ↑	25.6% (7–12 mo); 29.5% (13–24 mo) ↑	44.8% (7–12 mo); 63.1% (13–24 mo) ↑
Ahmed et al (2016)45	September 2012–January 2013	6–60 mo (720)	NR	55.8% (24.7% severely wasted) ↑	NR
Kejo et al (2018)72,c	NR	6–59 mo (436)	50%↑	16.5% ↑	28% ↑	TDHS and MIS 2015–2016 Stunting, 34%; wasting, 5%; underweight, 14% MoHCDGEC et al (2016)118
Mrema et al (2021)78	December 2016–January 2017	6–59 mo (341) (n = 200 lowland areas; n = 141 highland areas)	Lowland: 41.0% and (Highland: 64.5%) ↑	Lowland: 2.5% and (Highland: 1.4%) ↓	Lowland: 11.5% ↓ Highland: 22.0% ↑
Mtonga and Nyaruhucha (2022)79	October 2022	6–59 mo (300)	54.3% (26.3% severely stunted) ↑	3.7% (1.3% severely wasted) ↑	23.3% (7% severely underweight) ↑	TDHS and MIS 2022 Stunting, 30% (severe stunting, 9%), wasting, 3.3% (severe wasting, 1%), underweight, 12% (severely underweight 3%) MoHCDGEC et al (2022)119

^aNational-level surveys are routinely conducted in most countries every 3 to 5 years to monitor populations and their health and to assess children's nutritional status at 1 point, resulting in sparse data for some specific years.

^bCase-control study- sampling bias may affect prevalence rates and should be interpreted cautiously.

^cThe data collection dates were unavailable; the authors used the national survey data closest to the publication date.

Abbreviations: APZ, agro-pastoral zone; AZ, agricultural zone; CBS, Central Bureau of Statistics; CDHS, Cameroon Demographic and Health Survey; CSAE, Central Statistical Agency Ethiopia; DHS, Demographic and Health Survey; EC, Eastern Cape; EDHS, Ethiopia Demographic and Health Survey; EPHI, Ethiopian Public Health Institute; FSNMS, Food Security and Nutrition Monitoring System; GDHS, Ghana Demographic and Health Survey; GSS, Ghana Statistical Service; ICF, International Classification of Functioning, Disability and Health; INS, Institut National de la Statistique; KDHS, Kenya Demographic and Health Survey; KZN, Kwa Zulu Natal; MDHS, Mozambique Demographic and Health Survey; MIS, Malaria Indicator Survey; MISAU, Ministério da Saúde; MoHCDGEC, Ministry of Health Community Development Gender Elderly and Children; NBS, National Bureau of Statistics; NDHS, Nigeria Demographic and Health Survey; NISR, National Institute of Statistics of Rwanda; NPC, National Population Commission (Nigeria); NR, Not Reported; PZ, pastoral zone; RDHS, Rwanda Demographic and Health Survey; SDHS, South Africa Demographic and Health Survey; TDHS, Tanzania Demographic and Health Survey; UBOS, Uganda Bureau of Statistics; UDHS, Uganda Demographic and Health Survey; WFP, World Food Programme; ↑, the prevalence of childhood undernutrition is higher than that of national surveys; ↓, the prevalence of childhood undernutrition is lower than that of national surveys., Central Bureau of Statistics; CDHS, Cameroon Demographic and Health Survey; CSAE, Central Statistical Agency Ethiopia; DHS, Demographic and Health Survey; EC, Eastern Cape; EDHS, Ethiopia Demographic and Health Survey; EPHI, Ethiopian Public Health Institute; FSNMS, Food Security and Nutrition Monitoring System; GDHS, Ghana Demographic and Health Survey; GSS, Ghana Statistical Service; ICF, International Classification of Functioning, Disability and Health; INS, Institut National de la Statistique; KDHS, Kenya Demographic and Health Survey; KZN, Kwa Zulu Natal; MDHS, Mozambique Demographic and Health Survey; MIS, Malaria Indicator Survey; MISAU, Ministério da Saúde; MoHCDGEC, Ministry of Health Community Development Gender Elderly and Children; NBS, National Bureau of Statistics; NDHS, Nigeria Demographic and Health Survey; NISR, National Institute of Statistics of Rwanda; NPC, National Population Commission (Nigeria); NR, Not Reported; PZ, pastoral zone; RDHS, Rwanda Demographic and Health Survey; SDHS, South Africa Demographic and Health Survey; TDHS, Tanzania Demographic and Health Survey; UBOS, Uganda Bureau of Statistics; UDHS, Uganda Demographic and Health Survey; WFP, World Food Programme; ↑, the prevalence of childhood undernutrition is higher than that of national surveys; ↓, the prevalence of childhood undernutrition is lower than that of national surveys.

Study Characteristics

The study characteristics are detailed in Table S3. All 59 included articles reported on primary studies; 56 of these reported the results of cross-sectional surveys,^{1,42–57,59–66,68–91,93–99} one reported results of a longitudinal study,⁵⁸ and two reported results of unmatched case-control studies.^67,92 All included articles were published after 2000, and 54 of the 59 were published between 2011 and 2022.^{1,42–51,53–67,69–81,84–87,89–99}

The included studies were carried out in 11 SSA countries, including Ethiopia (n = 38; 64.4%)^{1,42–44,46,48,49,51,54–68,71,73,76,86,89–99}; the United Republic of Tanzania (n = 7; 11.9%)^{45,69,72,77–79,82}; two each (3.4% each) in Cameroon,^75,81 Ghana,^47,50 Kenya,^52,85 Nigeria,^53,83 and Uganda^70,84; and one each (1.7%) in Mozambique,⁸⁷ Rwanda,⁸⁰ South Africa,⁸⁸ and South Sudan.⁷⁴ Eastern and Southern Africa are most represented in the included articles (n = 55; 93.2%),^{1,42–46,48,49,51–74,76–80,82–99} with four included articles reporting on studies conducted in Western and Central Africa.^47,50,75,81 According to the World Bank’s country income classification,¹⁰ 50 of the included studies were conducted in low-income countries,^{1,42–46,48,49,51,54–74,76–80,82,84,86,87,89–99} eight in lower-middle-income countries,^{47,50,52,53,75,81,83,85} and one in an upper-middle-income country.⁸⁸

The number of participants in the 59 included studies ranged from 154 to 63 276 children typically paired with their biological mothers/caregivers. Four studies investigated nutrition status among orphans and vulnerable children.^51,61,90,93 Most studies (n = 42; 71%) assessed the nutrition status of infants and children aged 6 months to 5 years, with 11 studies including children within a narrower age bracket (ie, 6-24 months, 6-36 months, 12-59 months, 24-36 months, 24-59 months, or 36-59 months).^{55,57,58,63,66,76,77,83,89,91,97} Five studies included data on children younger than 6 months,^{1,52,53,75,82} and 1 study included data on children older than 5 years.⁸⁸ These six studies reported data on infants and children aged 6 months to 5 years separately.

All included studies collected anthropometric data to calculate the prevalence of stunting (height for age), wasting (weight for height), and underweight (weight for age) using WHO standard operating procedures.¹²⁰ Of the 59 included articles, 50 published data on the prevalence of stunting, 52 published data on the prevalence of wasting, and 46 published data on the prevalence of underweight. Furthermore, 50 articles reported on studies that explored the determinants of stunting, 47 explored the determinants of wasting, and 36 explored the determinants of underweight. None of the included studies investigated the prevalence or determinants of micronutrient deficiencies.

Prevalence of Undernutrition Among Infants and Children Aged 6 Months to 5 Years in SSA Countries

The prevalence of childhood undernutrition varied across the 59 included studies Table 2^1,42–99 and countries (Figure 2).

Figure 2.

The Prevalence of Undernutrition Among Infants and Children Aged 6 Months to 5 Years in Sub-Saharan African Countries. Underweight is a composite index of height-for-age (stunting) and weight-for-height (wasting) measures. As such, World Health Organization–United Nation Children’s Fund (WHO and UNICEF) do not provide prevalence thresholds for underweight. Prevalence distribution of stunting, wasting and underweight across 11 Sub-Saharan African countries. Maps of prevalence of the following in sub-Saharan African countries: stunting (A), wasting (B), and underweight (C). Prevalence thresholds of stunting and wasting were based on the WHO–UNICEF prevalence thresholds, with “very high” indicating a critical need for interventions.³⁸

Stunting

The prevalence of stunting was reported in 50 articles; of these, 31 reported on studies conducted in Ethiopia, with estimates ranging from 10.9% to 58.1%; 11 studies additionally reporting the prevalence of severe stunting, ranging from 4.9% to 36.9%. Five studies from the United Republic of Tanzania reported the prevalence of stunting, ranging from 8.4% to 64.5%, and 14 studies from other SSA countries reported a prevalence between 17.6% and 58.8%. Of the 50 studies that assessed the prevalence of stunting, 28 studies (56%) reported stunting prevalence higher than that of the relevant national surveys, with 34 studies (68%) reporting a very high prevalence of stunting (≥30%) according to the WHO–UNICEF prevalence thresholds.

Wasting

The prevalence of wasting was reported by 52 studies; of these, 33 studies were conducted in Ethiopia, with estimates ranging from 4.4% to 37.8%, with 12 studies additionally reporting the prevalence of severe wasting ranging from 1.3% to 5.8%. Six studies from the United Republic of Tanzania reported the prevalence of wasting ranging from 1.4% to 55.8%, and 13 studies from other SSA countries reported wasting, with estimates ranging from 1.3% to 58.2%. Of the 52 studies reporting on the prevalence of wasting, 31 (60%) reported prevalence of wasting higher than that of the relevant national surveys, and 16 studies (31%) reported a very high prevalence of wasting (≥15%) according to the WHO–UNICEF prevalence thresholds.

Underweight

The prevalence of underweight was reported by 46 studies; of these 26 studies were conducted in Ethiopia, with estimates ranging from 6% to 49.2%, with 10 studies also reporting on the prevalence of severe underweight, ranging from 3% to 21.9%. Six studies from the United Republic of Tanzania reported undernutrition estimates ranging from 5.7% to 63.1%, and 14 studies from other countries reported a prevalence of childhood undernutrition from 1.6% to 56.4%. Of the 46 studies that evaluated the prevalence of undernutrition, 26 (57%) reported a higher prevalence of underweight than that of the relevant national surveys. Table 2^1,42–99 shows variations in the prevalence of stunting, wasting, and underweight in infants and children aged 6 months to 5 years in SSA countries.

Determinants of Undernutrition Among Infants and Children Aged 6 Months to 5 Years in SSA Countries

Various determinants were reported as being significantly associated with childhood undernutrition by the 59 included studies (Figure 3), including child-related factors (immediate determinants), household-related factors, and maternal-related factors (underlying determinants).²⁹

Figure 3.

Determinants of Undernutrition Among Infants and Children Aged 6 Months to 5 Years in Sub-Saharan African Countries. The determinants were classified according to the United Nation Children’s Fund conceptual framework of maternal and child nutrition.³⁹ Child-related factors were classified as immediate determinants, and household- and maternal-related factors were classified as underlying determinants

The determinants most associated with stunting were child's age (>24 months; n = 23), male sex (n = 17), maternal illiteracy (n = 11), and low household socioeconomic status (n = 9). The determinants most associated with wasting were child's age (<24 months; n = 12), child unwell in the past 2 weeks (n = 10), male sex (n = 8), and not being exclusively breastfed for the first 6 months (n = 8). Finally, two determinants were frequently associated with underweight: child's age (>24 months; n = 17) and male sex (n = 10).

DISCUSSION

This comprehensive and systematic review of the literature on undernutrition among infants and children aged 6 months to 5 years in SSA countries, provides an up-to-date summary of the evidence on the prevalence and determinants of childhood undernutrition. The stunting prevalence across the 11 countries included in this study ranged from 8% to 64%, the wasting prevalence ranged from 1% to 58%, and the prevalence of underweight ranged from 2% to 63%. The most frequently reported determinants of childhood undernutrition were the child's age (>24 months), male sex, maternal illiteracy, diarrhea or illness in the past 2 weeks, low household socioeconomic status, or living in a larger household (n > 4 members). The prevalence of childhood undernutrition reported by primary studies is often higher than the prevalence reported in national surveys. Wasting and underweight are important measures of childhood undernutrition and can increase the risk of death, however, both are treatable and reversible.¹³ Stunting, on the other hand, can result in severe and irreversible physical and cognitive damage, with the consequences often lasting a lifetime and even affecting the next generation.¹³

The countries identified as having a prevalence of stunting within the very high category (≥30%) in this review included Ethiopia, the United Republic of Tanzania, Uganda, Rwanda, Kenya, Cameroon, and Mozambique. According to 2022 data from UNICEF, WHO, and the World Bank, the 17 SSA countries with a very high prevalence of stunting were Angola, Benin, Burundi, Central African Republic, Chad, Republic of the Congo, Eritrea, Ethiopia, Lesotho, Madagascar, Malawi, Mozambique, Niger, Nigeria, Sudan, United Republic of Tanzania, and Zambia.¹³ The countries identified as having a prevalence of wasting within the very high category (≥15%) in this review included Ethiopia, the United Republic of Tanzania, Uganda, and Rwanda; the two SSA countries identified as having a very high prevalence of wasting in the report by UNICEF, WHO, and the World Bank were South Sudan and Sudan. However, our review did not identify any primary studies that met inclusion criteria from some of these countries, indicating that there is limited primary research on the prevalence and determinants of childhood undernutrition in these countries.

The prevalence of undernutrition among infants and children aged 6 months to 5 years reported by the primary studies included in this review differed or varied from previous estimates, with most studies reporting that childhood undernutrition was higher than the national prevalence.^46,49,75,88 This finding is supported by previous research. A cross-sectional study conducted in a rural district in the northeast of Ethiopia reported a higher prevalence of wasting (16.2% vs 7.1%) and underweight (43.1% vs 21%) than those reported by the Ethiopia Demographic Health Survey in the same year.⁶⁴ Kejo et al⁷² suggested that the prevalence of childhood undernutrition in the predominantly rural Arusha District in the United Republic of Tanzania is high compared with national-level trends, suggesting that stunting prevalence was twice that of the national prevalence reported by the Tanzania National Nutrition Survey, and considerably higher than the prevalence reported in the Tanzania Demographic and Health Survey. Likewise, underweight and wasting prevalence remains unacceptably high, with the prevalence of childhood undernutrition reported by primary studies exceeding those reported in national surveys.⁷²

Although the demographic surveys provide national data on child nutritional status, data at district levels are not provided, limiting the capacity to develop interventions to mitigate childhood undernutrition contextualized to specific districts.⁷⁷ National surveys may underestimate the prevalence of childhood undernutrition in SSA countries. These surveys are based on national-level country data, which are generally collected sporadically in most countries and may not appropriately represent vulnerable geographic settings such as rural and remote areas.^27,121 Furthermore, stunting often goes unrecognized in communities as an irreversible indicator and a reflection of chronic deficiency and can take years to be noticed,¹⁶ whereas wasting is an acute condition that can appear in the short term and can change rapidly.¹²² A child with wasting could recover and then experience wasting again in the same year.¹²² The risks and prevalence of wasting can be driven by seasonal variations such as postharvest season, which is often characterized by higher food availability and weather patterns that are less likely to cause illness, and the preharvest season, which is often associated with food insecurity, torrential rains, and related morbidities that can adversely affect child's nutritional status.¹⁴ Alemayehu et al⁴⁶ reported a high proportion of wasting (34.6%) and severe wasting (23.3%) compared with the Ethiopia Demographic Health Survey, which was likely due to seasonal variations.

The most frequently reported determinants of childhood undernutrition were the child's age, male sex, maternal illiteracy or lack of education, diarrheal illness in the past 2 weeks, low household socioeconomic status, household family size (n > 4 members), and having a dietary diversity of less than the recommended five food groups. Several previous reviews also focused on the determinants of childhood undernutrition in SSA countries.^2,27,29,30 The systematic review by Akombi et al,²⁹ which included 49 studies published between January 1990 and January 2017, reported similar findings, with the most consistent factors associated with childhood stunting, wasting, and underweight in SSA countries identified as low education in mothers, increasing age in children, male sex, living in a poor household, prolonged duration of breastfeeding (>12 months), low birth weight and birth size, mother's age (<20 years), having an unimproved source of drinking water, having a mother with a low body mass, diarrheal episodes, low education in father's, and living in a rural location. Understanding the determinants most associated with childhood undernutrition can support the development of targeted strategies to address the determinants and reduce the risk of stunting, wasting, and undernutrition.

Male sex was identified as a significant risk factor for childhood undernutrition in most primary studies across SSA countries.^43,46,53,94 Male infants and children are more vulnerable to childhood undernutrition due to complex factors evolving over time, including intrauterine development, physiological and endocrine differences, higher susceptibility to infectious diseases, and differences in energy requirements and body composition.¹²³ Previous research has indicated that male children often consume fewer than the recommended minimum three meals per day.^49,51,81 In contrast, female children are more likely to experience wasting and be underweight due to male dominance and gender inequalities, which demand more physical household work from girls than boys.⁷⁵

The age of children was a significant risk factor for childhood undernutrition among infants and children under 5 years old; however, the results were complex, with 30 studies indicating that children older than 24 months were at higher risk of undernutrition and 10 studies reporting that children younger than 24 months were at higher risk. Previous research has suggested that children older than 12 months were more likely to have stunting than were infants, due to the age of initiation of complementary feeding and the risk of diarrheal morbidity.^1,44,50,59 Older children are more likely to experience stunting than infants, with the period from 6 months on being the peak time for stunting, micronutrient deficiencies, and infectious diseases.^124,125 This period is when a child is most sensitive to the impacts of poor nutrition.¹⁸ Additionally, overcrowding, low maternal income, and using infant formula for infants and children aged 6 months or older are associated with a higher prevalence of wasting and underweight.⁵³

Childhood undernutrition in SSA countries is significantly associated with numerous factors such as maternal education status, the mother's age, antenatal care attendance, and maternal handwashing practices.^55,65,82 In Ethiopia, a cross-sectional study of infants and children aged 6 months to 5 years found that maternal education significantly influenced stunting, with children of literate mothers 63% less likely to be malnourished than their counterparts with illiterate mothers.⁶⁰ Parental education reduces the risk of childhood undernutrition because higher education results in changes in parental values, improves household income and the allocation of resources toward children's health, and improves parents' health and nutrition knowledge.¹²⁶ Furthermore, educated mothers may influence their children's feeding practices, recognize early symptoms of undernutrition, and may be more likely to seek healthcare than their uneducated counterparts.⁶⁰

Personal hygiene practices, such as critical hand washing with clean tap water and soap, have proven to be the most affordable and effective way to reduce the transmission of infectious diseases and diarrhea.^127–129 Eight studies included in this review indicated that poor maternal hand hygiene during critical times, such as after latrine use or changing infants and children, and before food preparation and child's feeding, was a significant determinant of childhood undernutrition.^55,66,87,94 Diarrhea and lack of handwashing by mothers were commonly associated with higher rates of wasting. Diarrhea is both a cause and effect of childhood undernutrition, with diarrheal illnesses impairing gains in weight and height, and malnutrition leading to increased frequency and duration of diarrheal illnesses.¹³⁰ Additionally, other recent illnesses, such as fever, upper respiratory infection, anemia, and malaria, were also significant predictors of wasting among infants and children aged 6 months to 5 years in SSA countries.^57,61,67,86 A facility-based, unmatched case-control study from south Ethiopia suggested that infection plays a critical role in the etiology of undernutrition, due to various factors such as nutrient losses from vomiting, low appetite, diarrhea, poor digestion, malabsorption, and use of nutrients and increasing metabolic requirements.⁶⁷

Low household wealth status was also identified as a significant determinant of childhood undernutrition.^74,75,87 Infants and children aged 6 months to 5 years of families with higher monthly incomes have a lower risk of stunting, likely due to improvements in purchasing power to support children to have access to nutritious and diversified food.⁶² Households with larger families were identified as a significant determinant of undernutrition among infants and children aged 6 months to 5 years. In Ethiopia, infants and children aged 6 months to 5 years from large families of five or more members were more likely to experience wasting than infants and children from smaller families.⁷⁶ Similarly, infants and children aged 6 months to 5 years from families smaller than three members were 84% less likely to experience wasting than those from family sizes of >5.⁶⁷ The results further indicate that infants and children aged 6 months to 5 years from larger households may not receive adequate and well-balanced food for their growth and development, especially when economically inactive members increase relative to the number of economically active members.⁷⁶

Minimum dietary diversity less than the recommended minimum of five food groups daily was also identified as a determinant of childhood undernutrition among infants and children aged 6 months to 5 years in SSA countries. WHO, UNICEF, and the US Agency for International Development published indicators assessing Infant and Young Child Feeding Practices in 2008.¹³¹ The Minimum Acceptable Diet, a composite indicator, is one of the core indicators identified to assess Infant and Young Child Feeding practices at the population level.¹³¹ This indicator includes minimum dietary diversity (ie, quality aspect of complementary food) and minimum meal frequency (ie, quantity aspect of complementary food) and is calculated for both breastfed and non-breastfed infants and young children.¹³¹ An observational study investigating infants and children aged 6–59 months in rural Ethiopia found that child meal frequency of fewer than three times per day, low dietary diversity, and consuming leftover food were significant risk factors for wasting.⁹⁸ However, UNICEF and WHO recommend that infants and children at this age should consume at least 5 of 8 food groups daily to grow, develop, and learn.³⁹ Therefore, addressing family-level risk factors, which are significant drivers of children's nutritional status, is crucial to ensure adequate nutrition.⁹⁸

Multiple forms of malnutrition can burden SSA countries, particularly when those countries are affected by conflicts, political instability, and the burden of infectious diseases and parasites.^9,20,132 The impacts of the COVID-19 pandemic, climate change, and the Russian invasion of Ukraine have resulted in increased prevalence of childhood undernutrition in most developing countries, including SSA countries, due to food insecurity, disrupted supply chains, increased prices of grain, fertilizer, and energy¹³³; limited access to essential nutrition services and programs; and income losses.^14,23,134 It is estimated that COVID-19 has resulted in an additional 130 000 deaths globally in children younger than 5 years, due to reduced healthcare access and food supplementation, with 52% of these deaths occurring in SSA countries alone.¹³⁵ The 2022 Global Nutrition Report noted that COVID-19 exposed the vulnerability and weaknesses of already-fragile food systems, with millions of households in formerly food-secure regions of the world falling into severe food insecurity within the space of a few weeks.²² As such, the gains some countries had made in reducing hunger and malnutrition may have been lost during the pandemic.⁷ According to the United Nations, wheat prices increased by 45% in the first three months of the war in Ukraine, which substantially affected African countries because 44% of the wheat imported between 2018 and 2020 came from Ukraine and Russia, with five SSA countries (ie, Benin, Djibouti, Eritrea, Sudan, and the United Republic of Tanzania) importing >70% of their wheat from the region.^135,136 These current global challenges have further exacerbated childhood undernutrition in SSA countries. There is an urgent need to provide treatment to infants and children affected by undernutrition and to intensify preventive interventions that address the determinants of undernutrition.¹³⁷

Strengths and Limitations

The main strength of this systematic scoping review is that, by using peer-reviewed primary studies exploring childhood undernutrition at a community level, it provides a unique, up-to-date summary of childhood undernutrition. We included 59 articles reporting on studies that independently obtained anthropometric data and provided a detailed description of the data collection procedures (Table S3). We applied no date or language restrictions. Previous reviews primarily explored either the prevalence or the determinants of childhood undernutrition and often relied on secondary data sets. Our systematic scoping review provides a more comprehensive overview of the issue by exploring both the prevalence and determinants of undernutrition among infants and children aged 6 months to 5 years in SSA countries and comparing data from independent primary studies with national survey data, addressing a significant gap in the evidence in this vulnerable region. Although national data sets have limitations, they are valuable, and some national household surveys may have representativeness.

This systematic scoping review has some limitations. The characteristics of the studies included in this systematic scoping review were unexpected. Despite applying no date restrictions, all included studies were published after 2000, with 55 of the included studies published between 2011 and 2022. This is likely due to the recent introduction of significant global nutrition policies and initiatives to address the pervasive problem of malnutrition, including the development of Global Nutrition Targets and the Sustainable Development Goals, respectively. Most of the included studies (n = 38 of 59) were conducted in Ethiopia, which is likely due to Ethiopia's high rates of undernutrition and challenging political situation (ie, war and conflicts) and environmental factors, including but not limited to natural disasters such as droughts and floods that usually trigger food shortages or insecurity.⁶¹ Research suggests that >85% of the Ethiopian population depends on rain-fed subsistence agriculture and livestock husbandry, and the nomadic nature of the population results in more infants and children with acute malnutrition or wasting.^61,64 In addition, Ethiopia reported the worst food crisis in 2018. Studies revealed that food insecurity is a serious problem, especially since most people live in rural and remote settings which are disproportionately affected by food insecurity.⁹¹

Interestingly, none of the 59 included studies assessed micronutrient deficiencies among infants and children aged 6 months to 5 years in SSA countries. Micronutrient deficiencies such as iron, vitamin A, vitamin B₁₂, iodine, and others are reported to be alarmingly high across several countries in SSA, with children aged <5 years and pregnant women at the most significant risk of developing deficiencies.^138,139 Measuring micronutrient deficiencies in infants and children younger than 5 years often requires invasive tests, such as obtaining blood samples.¹⁴⁰ Researchers conducting studies on childhood undernutrition in SSA countries may be deterred from including measures of micronutrients for this reason.

We did not search the grey literature or include unpublished studies, which may have resulted in publication bias. The prevalence of undernutrition among infants and children aged 6 months to 5 years in SSA countries reported in this review must be interpreted with caution because the study participants may not represent the entire country. This review included 56 studies reporting data from cross-sectional surveys. Data from cross-sectional studies represents a particular point in time and should not be used to derive causal relationships.¹⁴¹ Additionally, two studies from Ethiopia were case-control studies, and the prevalence rates reported may be affected by sampling bias and therefore should be interpreted with caution. Finally, we did not conduct any risk-of-bias or quality assessment of the included studies, because they are not required for the 2018 PRISMA extension for scoping reviews.³³

CONCLUSION

Childhood undernutrition is a persistent, multifaceted public health challenge that continues to substantially affect the lives of infants and children aged 6 months to 5 years living in SSA countries, preventing them from reaching their full physical and cognitive potential. Understanding the prevalence and determinants of undernutrition among infants and children aged 6 months to 5 years can assist researchers, stakeholders, and policymakers in developing effective evidence-informed interventions to address childhood undernutrition in SSA countries. The prevalence of childhood undernutrition reported by primary studies is often higher than the data reported in national surveys, indicating that researchers, stakeholders, and policymakers should consider both primary and secondary data when evaluating or addressing childhood undernutrition in SSA countries. The determinants of childhood undernutrition are a complex interplay of various factors. The development of interventions to alleviate childhood undernutrition in SSA countries should aim to address the immediate, underlying, and enabling determinants. Interventions to address childhood undernutrition should primarily focus on reducing the risk of stunting, an irreversible condition, by considering the determinants most associated with stunting: child's age, male sex, maternal illiteracy, and low household socioeconomic status. Additionally, future research should explore the prevalence and determinants of micronutrient deficiencies by using noninvasive tests to identify deficiencies in infants and children aged 6 months to 5 years in SSA countries.

Author Contributions

All authors meet the criteria for authorship. F.P.R. contributed to the conception and design of the work and all processes and activities involved in the review, including drafting the final manuscript. K.O.J. contributed to the conception and design of the work, full-text screening, data extraction checking, data interpretation, and critical revision of the final manuscript. M.A.J. contributed to the conception and design of the work, the title and abstract screening, data extraction checking, data interpretation, and critical revision of the final manuscript. A.A.M. contributed to the conception and design of the work, data interpretation and critical revision of the final manuscript. All authors approved the manuscript and this submission.

Supplementary Material

Supplementary Material is available at Nutrition Reviews online.

Funding

This research received no specific grant from any funding agency, commercial or not-for-profit sectors.

Conflicts of Interest

None declared.