Demographic variation and socioeconomic inequalities associated with the triple burden of malnutrition in Vietnamese children aged 6 months to 9 years old: Findings from the Vietnamese General Nutrition Survey 2020

Introduction The triple burden of malnutrition (TBM) is a growing public health issue worldwide. This study examined the prevalence and association between undernutrition, overnutrition and micronutrient deficiencies (MNDs), and the associated demographic and socioeconomic determinants, among Vietnamese children, using the nationally representative General Nutrition Survey 2020. Methods Data on anthropometric parameters, micronutrients biomarkers, demographic and socioeconomic indicators for 7,289 children aged 6 months to 9 years old were analysed. Determinants of malnutrition were assessed using logistic regressions and reported as odds ratio (OR) [95% confidence intervals (CI)]. Results Overall, 12.7%, 10.5% and 4.7% of children were stunted, underweight and wasted/thin; while 7.3% and 7.1% were living with overweight and obesity, respectively. Low serum zinc, anaemia and iron deficiency (ID) were the common MNDs observed, affecting 53.1%, 15.2% and 13.9% of the study participants. Older children aged 2-4 years old [OR (95% CI): 1.43 (1.20, 1.72)], ethnic minorities [5.94 (3.78, 9.36)] and living in mountainous areas [5.06 (1.18, 14.42)] had increased odds of stunting, whereas reduced odds were found in children from the richest quintile [0.13 (0.05, 0.32)]. Similar determinants were found to be associated with underweight and MNDs. Males [1.43 (1.16, 1.76)], children aged 5-9 years old [10.02 (6.71, 14.97) and children from the richest quintile [2.91 (1.20, 7.05)] had increased odds of overweight. Children with anaemia, low serum retinol and low serum zinc had increased odds of stunting and underweight than non-micronutrient deficient children (adjusted OR=1.43-1.71). Compared to children without MNDs, those with ≥3 MNDs had almost double the odds of stunting and underweight, whereas those with ≤3 MNDs had reduced odds of overweight (adjusted OR=0.38-0.60). Conclusions Significant demographic variation and socioeconomic inequalities in child malnutrition were identified. National policies and programmes in Vietnam should address age-specific, sex-specific, geographical and socioeconomic disparities to accelerate progress in reducing child malnutrition. What is already known on this topic? summarise the state of scientific knowledge on this subject before you did your study and why this study needed to be done What this study adds? summarise what we now know as a result of this study that we did not know before How this study might affect research, practice or policy? summarise the implications of this study ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work was undertaken as part of the project entitled Addressing micronutrient deficiencies associated with the double burden of childhood malnutrition in China, a combined food system framework, which funded by UK Biotechnology and Biological Sciences Research Council (BBSRC) (Grant number: BB/T008989/1). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The GNS 2020 was reviewed and approved by the Ethical Committee of the National Institute of Nutrition (NIN), Ministry of Health, Vietnam. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes