All studies published in English between 1980 and 2024 were included in the review. A comprehensive search of original articles was performed using five electronic bibliometric datasets- JSTOR, SCOPUS, PubMed, Web of Science and MEDLINE. The following terms and keywords were used in the search: Refugee: “refugee’s”[All Fields] OR “refugees”[MeSH Terms] OR “refugees”[All Fields] OR “refugee”[All Fields] AND children: “child”[MeSH Terms] OR “child”[All Fields] OR “children”[All Fields] OR “child’s”[All Fields] OR “children’s”[All Fields] OR “children’”[All Fields] OR “child’”[All Fields] AND South Asia: “asia, southern”[MeSH Terms] OR (“asia”[All Fields] AND “southern”[All Fields]) OR “southern asia”[All Fields] OR (“south”[All Fields] AND “asia”[All Fields]) OR “south asia”[All Fields] OR “Afghanistan”[All Fields] OR “Bhutan”[All Fields] OR “Pakistan”[All Fields] OR “India”[All Fields] OR “Bangladesh”[All Fields] OR “Nepal”[All Fields] OR “Maldives”[All Fields] OR “Sri Lanka”[All Fields] OR “Maldives”[All Fields] AND Nutritional Status: “nutritional status”[MeSH Terms] OR (“nutritional”[All Fields] AND “status”[All Fields]) OR “nutritional status”[All Fields] OR “stunting”[All Fields] OR “wasting”[All fields] OR “underweight”[All Fields] OR “overweight”[All Fields] OR “obesity”[All Field].

The inclusion criteria used the CoCoPop mnemonic (Condition, Context and Population) approach to determine the prevalence of nutritional status in refugee children of South Asian countries from the original articles (16).

The inclusion criteria for the peer-reviewed research articles included observational study designs (i.e., cohort, cross-sectional, and case–control designs) for the estimation of the pooled prevalence estimates. Exclusion criteria comprised of research articles focusing on the Internally Displaced persons (IDPs), returned IDPs, naturalized refugees, and resettled refugees. Using the above exclusion criteria gray reports solely defining the integrated care, published in language other than English, population greater than 19 years of age and lacking the inclusion of South Asian countries were not listed for the present review (Table 1).

The original research articles that were retrieved were uploaded to COVIDENCE 2.0, a systematic review software by Veritas Health Innovation (17) to conduct the review. This software facilitates an unbiased screening process for selecting research articles for inclusion in the systematic review. The selection of articles for current systematic review was completed in four steps: firstly, uploaded the RIS/PubMed files to the COVIDENCE 2.0 software and removed duplicates; secondly, two reviewers independently screened the title and abstracts (TL and RSB); thirdly, after retrieving the full-text article, duplicate screening of full-text articles was conducted based on inclusion eligibility criteria (TL and RSB); and finally, the included research articles were incorporated for the systematic review and meta-analysis. Disagreements regarding study inclusion for full-text review were resolved through discussion and consensus with a third co-author (KM) and discrepancies were resolved.

Two authors independently performed the data extraction from eligible full-text articles. Discrepancies in data extraction were addressed through a meeting at the end of double extraction, with unresolved issues settled by PP. A Microsoft Excel spreadsheet was used for data extraction, and tables were prepared. From the eligible studies, information was collected, including the author’s name, publication year, study location, country of residence for refugees, study design, number of participating refugee children, and prevalence of malnutrition in four categories: underweight, stunting, wasting, and overweight/obesity in refugee children up to 19 years of age. The gray literature data extraction included reports stating the title of report, agency of publication, age of population, prevalence data of underweight, overweight, stunting and wasting.

The Joanna Briggs Institute (JBI) critical appraisal tool for systematic reviews was used for critical appraisal of each article included in the study (16). The JBI critical appraisal tool for prevalence studies had nine questions in the checklist, and each question fell into one of four criteria: ‘yes,’ ‘no,’ ‘unclear,’ or ‘not applicable.’ Each checklist score was tallied and could have a maximum score of nine and a minimum of zero. A score between 0 and 3 was considered as low, 4–6 as medium, and 7–9 as high.

The data extracted was summarized based on the objective of the present review. The characteristics of the included studies were summarized, including author, year, age group of children, country of origin, sample size, and sub-categorized into rural–urban locations. Further, the prevalence of undernutrition underweight (WAZ < -2), stunting (HAZ < -2), wasting (WHZ < -2) and overnutrition indicators such as overweight (BMI-for-age Z score > +1 to +2 and WHA > 2) and obesity (BMI-for-age Z Score > +2), from the included studies were presented in the tables (18).

Meta-analysis was performed to estimate the pooled prevalence of malnutrition. A pooled estimate of underweight, stunting, wasting, and overweight prevalence was derived using a random-effects model (Dersimonian–Laird method) using MedCalc statistical software (version 22.018, MedCalc Software Ltd., Belgium). The random-effects model was used due to higher study variations. The MedCalc software was used for developing forest plots and analyzing the heterogeneity of the included studies (19). Given the diversity in geographical locations, sample sizes, participant ages, and outcome indicators across the retrieved studies, statistical heterogeneity was evaluated using Cochran’s Q and I² statistics (I² > 75% indicates substantial heterogeneity). Publication bias was evaluated using Egger’s test and Begg’s rank test and represented as the Funnel plot; a p-value <0.05 indicated the publication bias. Similarly, reports from various organizations supporting the welfare of the refugee children, migrants, and international agencies were listed manually. The presence of data from the gray literature was presented as “▲” (available) and “-” (unavailable). The data for gray literature was narratively synthesized.

The study analyzed 10 research articles and 11 gray literature reports that met the inclusion criteria. The results were compiled and analyzed through meta-analysis for the prevalence of malnutrition, while gray literature was summarized narratively.

A total of 9,752 research articles were retrieved from five databases from 1980 to 2024. The Covidence 2.0 software was used for duplicate screening of research articles. Out of the 9,752 articles imported to the Covidence 2.0 software, 6,224 were identified as duplicates. Subsequently, the title and abstract screening were conducted for the remaining 3,528 articles, resulting in 1743 exclusion as the primary research articles did not conform to the CoCoPop mnemonic approach. The remaining 1785 research articles were further screened for full text based on eligibility criteria. About 1775 articles, 700 articles for non-matching age groups of participants, 300 studies for non-South Asian locations (countries), and 775 research articles on not defining the prevalence values of under and over-nutrition were excluded. Finally, 10 full-text research articles, all with cross-sectional study design were included in the systematic review (6, 7, 20–27) (Figure 1). Additionally, gray literature consisting of reports from reputed organizations (n = 11) were included in the present review for strengthening the current review on the prevalence of malnutrition in refugee children from South Asian countries (28–37) (Figure 1).

A quality assessment of the included primary research articles was conducted using the JBI checklist for prevalence studies and the results showed that most studies were of high quality (a score of >7 out of 9). Out of 10 included studies, eight studies had complied on all the nine critical appraisal questions (i.e., the studies included sample frame to address the target population, analysis of the samples, sample size, study settings, coverage of the data, identification of the conditions, standard and reliable methods for study participants, appropriate statistical analysis and response rates of the participants) (Figure 2).

The included studies represented four countries in the South Asian region: Afghanistan (n = 2), Bhutan (n = 1), Bangladesh (n = 6) and India (n = 1) (Table 2). The 10 studies included in the present review covered a total of 4,274 participants with 3,536 urban and 738 rural refugee children, and the studies followed a cross-sectional study design. The ages of the participants ranged from 0 to 19 years [refugee children (n = 8) and refugee adolescents (n = 2)]. Of the 10 studies, eight were from urban and two from rural locations. The sample size of the included studies varied between 58 (from Afghanistan) to 1,087 (from Bangladesh) refugee children. Most of the studies covered childhood prevalence of malnutrition among refugee children (n = 6) from Bangladesh. All included studies were published between 1994 and 2023 (Table 2).

The included studies used standard anthropometric indicators to assess childhood nutritional status. Indicators of malnutrition used included underweight (WAZ < -2), stunting (HAZ < -2), wasting (WHZ < -2) and overweight (BMI-for-age Z Score > +1 to +2 and WHZ > +2) and obesity (BMI-for-age Z Score > +2).

Seven included studies showed the prevalence of underweight (6, 7, 20–22, 26, 27); nine studies reported stunting (6, 7, 20–27) and eight studies reported for wasting (6, 7, 21–25, 27). On the other hand, three studies reported the prevalence of overweight (6, 7, 22), and two studies obesity among refugee children (6, 7) (Table 3).

The highest prevalence of stunting and wasting was reported in in refugee children living in Bangladesh (75.4, 24.3%, respectively) (26, 27), and underweight (65%) in Afghani children (24). An Indian study reported the lowest prevalence of stunting (3.9%) (20). Wasting remained as the nutritional challenge - Bangladesh refugee children showed the highest prevalence of wasting (24.3%), followed by Afghanistan refugee children (15.9%) (7, 24). Among refugee adolescents, those from Afghanistan had the highest level of stunting (35.3%), followed by Nepal (26.9%) (Table 3).

Notably, half of the studies reported a very high prevalence of stunting of public health emergency (i.e.,>30%) (6, 7, 22–24, 27). Further, two studies reported high (20–30%) (6, 21), and one medium prevalence (10–20%) (25) of public health concern. Similarly, three out of eight studies reported a very high prevalence of wasting (>15%) (7, 23, 24), two studies high (10–15%) (6, 22), and one study medium (5–10%) (21) prevalence of public health emergency (Table 3).

Surprisingly, two studies from Bangladesh and one study from Afghanistan reported overweight and obesity among refugee children (6, 7, 22). Two authors studied refugee children from urban areas (6, 22), while one study focused on refugee children from rural areas (7). Afghan rural refugee adolescents had the highest prevalence of overweight (24%) and obesity (5.2%) than urban studies (7). Overnutrition was prevalent among refugee adolescents compared to refugee children under five (6, 7) (Table 4).

Pooled estimates were calculated through meta-analysis software to summarize the prevalence of undernutrition and over nutrition in refugee children living in South Asia. Although the prevalence of stunting ranged from 3.9 to 75.4% in the included studies, the overall pooled prevalence of stunting was 31.8% (95% CI: 18.6 to 46.6%; Supplementary Table S1, Figure 3). A high heterogeneity was observed between the included studies (I²: 98.9); p < 0.0001 (Figure 3). The Egger’s test showed no statistically significant publication bias in the overall prevalence analysis of stunted refugee children (p = 0.9) (Figure 4).

Similarly, the prevalence of underweight varied between 4.4 to 65% in the included studies, and the estimated pooled prevalence of underweight was 19.1% (95% CI: 10.8 to 29.2%) (Supplementary Table S2; Figure 5). Higher heterogeneity was observed between the included studies (I²: 96.8%); p < 0.0001 (Figure 5). The Egger’s test showed no significant publication bias in the overall prevalence analysis for undernourished refugee children (p = 0.3) (Figure 6).

Further, the prevalence of wasting ranged from 0.3 to 24.3% in the included studies, and the estimated pooled prevalence of wasting was 10.1% (95% CI: 4.6 to 17.3%; Supplementary Table S3, Figure 7). A high heterogeneity was observed between the included studies (I²: 97.5%); p < 0.0001 (Figure 7). The Egger’s test showed no significant publication bias in the overall prevalence analysis for wasted refugee children (p = 0.09; Figure 8).

On the other hand, three studies from South Asia reported a prevalence of overweight between 3 to 24%, and the estimated pooled prevalence of overweight was 6.5% (95% CI: 2.6 to 12.1%; Supplementary Table S4, Figure 9). Higher heterogeneity was observed between the included studies (I²: 80.28%; p = 0.01; Figure 9). The Egger’s test showed no significant publication bias in the overall prevalence analysis for over nourished refugee children (p = 0.8; Figure 10).

Time trend analysis of the prevalence of malnutrition was conducted using the prevalence rates reported in primary research articles. The prevalence of underweight in refugee children reported a decreasing trend while that of stunting and wasting, showed an increasing trend. A limited number of studies reported the prevalence of overnutrition, yet an increasing trend of prevalence in refugee children was noted.

For the present review, gray literature was searched manually for information, in addition to the original research articles, on the prevalence of malnutrition among refugee children in South Asia. The gray literature included reports and policy documents from various organizations, and the search results were summarized. Eleven reports from international organizations were obtained after the screening - four were from the United Nations High Commissioner for Refugees (UNHCR), three from UNICEF, two from the Centre for Disease Control and Prevention (CDC), and one each from Internal Displacement Monitoring Centre iDMC, IMPACT, Plan International (31), and Action Against Hunger (28–37).

Most of the refugee children were found to be concentrated in Bangladesh and Pakistan. Around 500,000 Rohingya children sought refuge in camps in Bangladesh. Similarly, it was reported that 90% of refugees in South Asia were originally from Afghanistan (36). A majority of the literature reported on children under five years, and information on the nutritional status of refugee children between five and nineteen was underreported, or the availability of factual data was limited. UNICEF (35) reported a 7.5% prevalence of severe acute malnutrition among Rohingya refugee children, which was double the rate compared to their six-month prior reports (35). The opportunity to corroborate of the prevalence results from original studies with that from the gray literature was limited as the comparable data was unavailable.

Additionally, the Kutupalong and Nayapara camps of Bangladesh reported high wasting and stunting in the under-five children. Overall, the reports focused on the social, demographic, and other related challenges and implications of malnutrition in refugee children of South Asia. However, information (data) on the prevalence of malnutrition was limited in the gray literature that otherwise addressed the challenges of refugee children, including food insecurity (Table 5).