Undernutrition is still highly prevalent in developing countries and leads to a multitude of problems as it weakens the immune system, which leads to increased risk of infections and diet-related diseases. COVID-19 has worsened the existing situation and has resulted in unprecedented health, social, and economic disruptions across the world. Before COVID-19, about 54% children under 5 years were moderately or seriously malnourished, and after the COVID-19 pandemic, early estimates suggest that an additional 2.6 million children were stunted; 9.3 million were wasted, with an addition of 2.1 million maternal anemia cases; 168,000 child deaths; and USD 29.7 billion in productivity losses. This review is mainly focused on the health and nutrition sectors and highlights the impact of COVID-19 on malnutrition, food system and industry, and it also discusses the various measures implemented across the world to cater the burden of maternal and child malnutrition. Movement restrictions and lockdowns within and across the countries/borders have imposed an unprecedented stress and shock on the food supply chain, affecting harvest, food processing, supply, logistics, food demand, shortages, and cost. Many countries have implemented interventions such as cash transfers, food ration distribution, insurance plans, utility subsidy, and tax exemptions to assist the population to cope with the financial and health issues caused due to the outbreak. Other than these measures, evidence recommends some essential direct and indirect interventions which could help in reducing malnutrition during COVID-19. The COVID-19 pandemic has re-demonstrated the connection between food systems, nutrition, health, and prosperity and the need for a more holistic approach.
COVID-19 has affected the food system and industry, which has contributed to increased food prices and increased rate of unemployment.
Among individuals with malnutrition, COVID-19 exacerbates the condition and increases the risk of morbidity and mortality.
Government, donors, and developmental partners have taken several steps to reduce the economical and health burden of people.
Direct and indirect interventions among pregnant women and children can also be implemented to reduce the burden of malnutrition during COVID-19.
Epidemiology of Global Malnutrition
Malnutrition is a major public health concern, which targets the most vulnerable populations including poverty-stricken and people with a compromised immune system . Malnutrition includes overnutrition (overweight and obesity), undernutrition (underweight, stunting, and wasting), and micronutrient excess or deficiencies . In the year 2020, globally, 1.9 billion adults were overweight or obese, while 462 million were underweight . While in the most vulnerable population of children under the age of 5 years, about 45 million were estimated to be wasted, 149 million were stunted, and 38.9 million were estimated to be overweight or obese . Also, around 45% of the deaths under the age of 5 years were linked to undernutrition, of which most of the deaths occurred in low- and middle-income countries (LMICs) (Fig. 1) [3, 4].
Malnutrition affects the global burden of disease economically, socially, developmentally, and therapeutically, by affecting people, their communities, children, and families with long lasting and serious health consequences . Children born as low birth weight (LBW) are unable to reach their full growth potential and are susceptible to illness, infections, and mortality in early life . Young children with compromised immune systems affected by malnutrition are also more susceptible to infectious diseases and are prone to long-term intellectual and psychological development defects and cognitive development delays with compromised mental and physical development [5, 6].
A recent study from 62 LMICs reported an overall prevalence of stunting, wasting, and underweight among children 0–59 months of age from years 2006–2018 to be 29.1%, 6.3%, and 13.7%, respectively . The regional level data in the study from Western Africa, Southern Asia, and Southeastern Asia indicated a relatively increased estimated prevalence of undernutrition as compared to the global estimates . A comparative analysis of the prevalence of malnutrition at a subregional and country level illustrated prevalence of wasting in Asia to be three percentage points greater than that of Africa and 7–8 percentage points greater than that of Europe, the Americas, and Oceania, whereas at the subregional level, substantial variations in the burden of wasting existed . The researchers further suggested that the regional-, subregional-, and country-level disparities in undernutrition do exist, and it is essential to bridge this gap to end malnutrition by 2030 .
Malnutrition should be catered in the first two years of life among children or even during the prepregnancy or pregnancy period before the symptoms begin to appear . Coinciding with the growth and mental development in children, protein energy malnutrition is a major problem, and this early window period is considered essential to prevent and manage acute and chronic malnutrition symptoms [8, 9].
Malnutrition, being a preventable public health issue, necessitates a multi-sectoral strategic approach which should be wisely implemented to eliminate stunting, wasting, and overweight . This situation further calls for an increased financial investment, alongside concerted efforts to be directed by the government organizations, policymakers, program managers, and relevant industry to eliminate the menace . The United Nations (UN) Decade of Action on Nutrition 2016–2025 and the Agenda for Sustainable Development by 2030 primarily hint at eliminating all forms of malnutrition. The World Health Organization (WHO) has also set an international target to reduce wasting to <5% by 2025 .
Global Burden of COVID-19
COVID-19 has resulted in unprecedented health, social, and economic disruptions across the world . Despite the continued and mixed use of masks, social distancing, lockdowns, and rollout of vaccines in many countries, so far, nearly five million people have lost their lives due to COVID-19, and about 250 million cases of COVID-19 have been reported worldwide . Based on the available stats, the majority of the coronavirus cases have been reported in the United States of America (USA) (45,220,057 cases), India (34,127,450), Brazil (21,680,488), the United Kingdom (UK) (8,630,076), and Russia (7,969,960), whereas the majority of the COVID-19-related deaths have also been reported in the USA (731,271), Brazil (604,228), India (452,811), Mexico (285,347), and Russia (222,320) (Fig. 2) [14, 15].
Impressive progress has been made with respect to COVID-19 vaccinations in many high-income countries (HICs); however, inequitable distribution of vaccinations across the world, especially in LMICs, remains a main challenge . According to the data, about 36.3% of the world population is fully vaccinated, and about 87.3% population of the United Arab Emirates (UAE), 85.5% population of Portugal, 84.6% population of Malta, and 82.1% population of Singapore are fully vaccination . In contrast, only 0.3% of the population is fully vaccinated for COVID-19 in South Sudan, 1.1% in Afghanistan, 8.0% in Iraq, 16.1% in Pakistan, and 20.6% in India . These numbers clearly state the low coverage of COVID-19 vaccine in LMICs .
Impact of COVID-19 on Malnutrition
Millions of people are impacted by the COVID-19 pandemic, especially those who live below the poverty line, particularly in countries of Asia and Africa . This is not because of the crowded conditions and challenge of handwashing and social distancing but majorly because of malnutrition as it increases the risks of getting ill and dying among the individuals [17‒19]. It weakens the immune system and leads to many diet-related diseases, and accompanied with these existing issues, COVID-19 worsens the situation and exacerbates malnutrition, infections, and chances of mortality . A Lives Saved Tool analysis suggests that COVID-19 disruptions with restrained access to healthcare and food systems could lead to significant increase in child mortality, and malnutrition could be a significant contributor to this increase in child mortality .
During COVID-19, diversion of limited resources for immediate medical needs, disrupted supply chain, devastated economy, weakened social safety nets, suspension of school feeding programs, increased political instability, increased cost of localized food, and disruptions in food and health systems have exacerbated maternal and child undernutrition across LMICs . Evidence from household surveys in Asia and Africa also reports large increases in poverty and food insecurity throughout 2020 [22‒26]. To cope with this, families have shifted to less expensive sources of energy, including cereals, starchy staples, and/or nonperishable ultra-processed foods, with reduced consumption of nutrient-rich vegetables, fruits, and animal-sourced foods, such as fish, meat, and dairy [27, 28]. These shifts have led to less nutritious and poorer quality diets, which in turn has increased the risks of undernutrition, especially micronutrient deficiencies (hidden hunger)  which has affected both high- and low-income countries . In HICs, hidden hunger coexisted with obesity due to increased intake of macronutrients (i.e., carbohydrates and fats) . Due to the COVID-19 surge, three billion people lacked access to nutritious diet, two billion people suffered from micronutrient deficiencies, one in three women of reproductive age suffered anemia, one in three people were either overweight or obese, and one-tenth of the worlds’ population was undernourished .
Before COVID-19, about 54% children under 5 years were moderately or seriously malnourished, of which most of them dwelled in Sub-Saharan Africa and Southern Asia . Estimates using the Modelling International Relations under Applied General Equilibrium model, the Lives Saved Tool, and Optima Nutrition tool for 118 LMIC countries suggest that by 2022, disruptions due to COVID-19 could result in an additional 2.6 million stunted and 9.3 million wasted children, with an addition of 2.1 million maternal anemia cases, 168,000 child deaths, and USD 29.7 billion in productivity losses due to excess stunting and child mortality . Kurtz et al. (2021)  reported that malnourished children under 5 years old (with a history of malnutrition) have increased odds of having severe COVID-19 as compared to teenagers. Similarly, there is an increased odds of severe COVID-19 among malnourished adults (with a history of malnutrition) between 18 and 78 years .
Apart from undernutrition, school closures during COVID-19 have also contributed to weight gain among children and adolescents due to decreased physical activity and increased sedentary lifestyle [33, 34]. A study reported an increase in meal frequency and 20.7% increase in intake of sweet and fried food during COVID-19 . During the lockdown, the obesity prevalence in China increased from 10.5% to 12.6% among high-school and college students . Studies from Palestine reported weight gain in 41.7% of the adolescents , a study from Spain reported a 25% increase , and a study from the USA reported weight gain in 15% of the adolescents during the pandemic . A study in Qatar also reported a 3–6 kg increase in body weight among adults aged ≥18 years . Prior to the pandemic, obesity was considered to be an issue in HICs, but an increase was also observed in LMICs during the pandemic . Obesity also increases the risk of severe illnesses due to COVID-19 . In the USA, children (less than 18 years) with obesity had a 3.07 times higher risk of hospitalization due to coronavirus, and there was a 1.42 times higher risk of severe illness (invasive mechanical ventilation, intensive care unit admission, or death) when hospitalized . Even among adults, high BMI among COVID-19 patients was associated with a 33% increased risk of hospitalization and a 61% increased risk of mortality among adults in the USA . The COVID-19 pandemic is expected to increase the risk of all forms of malnutrition; thus, all children at risk of malnutrition require nutritional care and support to address their nutritional needs [19, 43].
Impact of COVID-19 on the Food System and Industry
Movement restrictions and lockdowns within and across the countries/borders have imposed an unprecedented stress and shock on food supply chain, affecting harvest, food processing, supply, logistics, and food demand . Disrupted local and national food markets have caused steep reduction in the global economy [44, 45]. In developing countries, these disruptions have further worsened the vulnerability of livelihoods and food systems (e.g., agrifood systems) .
Looking into the crises in global perspective, observations are quite clearly indicating stability of the physical and technological infrastructure of the food industry unlike health services sector that was overwhelmed in its capacity . Contrarily, the food system failed to respond in its social interface . It would not be wrong to comment that COVID-19-linked food business impositions brought food services and hospitality industry to their knees . Apart of the business aspects, disruption of the food supply chain in food service and hospitality industries severely affected flow of consumer goods from farm to fork . Short-term and long-term suspension of food businesses severely hit businesses of fresh food supplies like fruits and vegetables, fish, and cheese which were replaced with supermarket standard products . Agri-tourism that also provides opportunities to local farmers and food entrepreneurs to diversify their income resources has also been collapsed with suspension of tourism, severely affecting economies which heavily rely on the tourism industry . Unlike small- and medium-size food businesses, fast-food business operators and beverages industries aggressively marketed ultra-processed foods and beverages whose regular consumption is associated with increased risk of obesity, noncommunicable diseases, and a higher rate of contract with the COVID-19 and associated mortality [51, 52].
According to the Global Food Crises Report 2020, about 135 million people from 55 countries faced a “crisis” level or higher level of acute food insecurity, and about more than 183 million people faced a “stressed” level of acute food insecurity . This situation commends urgent action before blowing into social and economic crisis . A UN report states that about 720–811 million people have gone to bed hungry in the year 2020, and about 118 million people have faced chronic hunger in 2020 compared to 2019 . It further added that about 30% of the world’s population had lack of access to food in the year 2020 . Thus, this pandemic has markedly increased the number of people facing acute food insecurity in 2020–2021 .
COVID-19 has a direct and an indirect impact on the food supply chain . Direct impact such as movement restrictions, lockdowns, closure of hotels and restaurants, and restriction on vendors has influenced the urban market . Lockdowns and disrupted trading have also impacted the harvesting and agricultural activities, availability of migrant labor, purchase, and postharvest losses [56, 57]. Some examples of the affected include mango producers in Pakistan, coffee growers in Columbia and Brazil, and livestock in the UK . Indirect impact of COVID-19 includes unemployment and reduced income . Many people working in retails and as casual labors have faced massive job losses, with a major drop in their income . According to the estimates by the International Labour Organization, about 345 million jobs were lost across the globe in the third quarter of 2020 [57, 59]. Loss of job and drop in income have been compounded with food shortages and increased food prices . Disruptions in the supply chain have also led to increased food prices . The economic downturn has affected the affordability of nutritious foods . In Sub-Saharan Africa, the nutritious foods such as fruits and vegetables are ten times more expensive than the staple food . In Syria, the monthly cost of food has been increased by 240% with increase in 1.4 million food-insecure people . The wheat cost in South Sudan in the year 2020 has increased by 62%, the price of maize in Kenya has increased by 60% since 2019, while the overall cost of food in Ghana jumped has to 33% in year 2020 .
The pandemic also led to suspension of many nutrition focused programs, for example, many school food programs across different countries were suspended due to school closures . A study reported food shortage, poor quality food, decreased meal frequency and portion, and increased child labor due to suspension of school feeding programs during COVID-19 in Ethiopia . However, despite the school closures, some countries like the USA, India, Nigeria, Columbia, Libya, Congo, Cambodia etc. continued their intervention through different strategies and modalities [63‒67].
Many countries are striving to support their citizens during this crisis, while some countries are being supported by different nongovernmental organizations and UN agencies to help people survive despite the challenges of COVID-19 . Few initiatives by countries are listed below:
Pakistan: the government introduced a program which provided cash grants of PKR 12,000 per household to the most vulnerable people and who have lost their jobs during the pandemic . The state has also provided support to the farmers by procuring wheat for sustainable supply in the country. An “Agriculture Package” was also introduced which provided financial assistance to farmers on inputs such as pesticides, seeds, fertilizers, and tractors to reduce their cost of production . The Ehsaas Nashonuma Programme was launched in 14 districts which aimed at reducing child stunting. It comprised of cash transfer, healthcare, and immunization for pregnant women and children and provision of specialized nutritious food to pregnant women, new mothers, and children .
Bangladesh: the World Bank mobilized USD 87.8 million in cash transfers as a part of “Livestock Dairy Development project” to 407,000 vulnerable poultry and dairy farmers to support their business .
Kyrgyz Republic: the World Bank-supported, “GAFSP-funded Agricultural Productivity and Nutrition Improvement Project” which aimed to improve water infrastructure and develop the capacity of water users’ associations . They also distributed USD 1.1 million for procurement of seeds and fertilizer through 30 projects .
Haiti: the “Resilient Productive Landscape project” helped over 16,000 farmers by mobilizing funds to access fertilizers and seeds to safeguard their production for cropping seasons .
Mozambique: United States Agency for International Development (USAID) in collaboration with the Development Finance Corporation provided loan guarantees to two local banks that helped supply food from rural producers to urban consumers, such as storage providers and transportation .
Maintenance of adequate nutrition and rehabilitation has been considered as the most effective intervention to reduce mortality due to malnutrition . Studies have suggested nutrition education as a suitable intervention for mothers to improve growth of their children in the first two years of life [71‒73]. While other interventions include exclusive breastfeeding in the first six months of life; deworming; vitamin A supplementation; food fortification; zinc treatment and rehydration salts for diarrhea; folic acid/iron for lactating and pregnant women; and improved access to piped water, hygiene, and sanitation [71‒73]. These interventions have shown positive effects on the prevention of malnutrition among children [71‒73]. Evidence-based interventions that contribute to improving maternal and child nutrition are a combination of direct (e.g., micronutrient supplementation, delayed cord clamping, breastfeeding promotion, and counseling) and indirect (e.g., water, sanitation and hygiene promotion, poverty alleviation, food security, women empowerment, and malaria prevention) interventions .
Evidence on direct interventions shows that maternal multiple micronutrient supplementation improves child growth in LMIC and helps reduce the risk of LBW by 15%, stillbirths by 9%, small-for-gestational age (SGA) babies by 7%, and preterm births by 4% . Provision of food supplements such as balanced energy protein during pregnancy also helps reduce the risk of stillbirth by 61%, LBW by 40%, and SGA births by 29% . Provision of supplementary food with the use of locally produced supplementary and therapeutic food in communities and in food-insecure settings have supported in the management of children with acute malnutrition . Provision of small-quantity lipid-based nutrient supplementation has also shown positive effects on growth among children 6–23 months old . It has shown to reduce the effect of stunting by 18% by 6 months of age, and it has also shown to reduce the risk of SGA births by 6% . Vitamin A supplementation to neonates in the South Asian region has shown to reduce the risk of mortality at 6 months by 13% .
Indirect nutrition interventions, such as preconception care, malaria prevention, water, sanitation, and hygiene promotion have also provided significant nutritional benefits . Birth spacing has shown to improve maternal nutrition outcomes and reduce the incidence of stunting by 10–50% among children in different contexts . A review of 17 trials reported that malaria chemoprevention during pregnancy reduces the risk of severe anemia by 40% and LBW by 27% and increases the birth weight by 93 g . These set of interventions, i.e., direct and indirect, can be useful upon implementation in response to COVID-19 to cater malnutrition. However, Keats et al.  2021 recommends a set of key interventions to address malnutrition, which are highlighted in Table 1.
Response to COVID-19 to Cater Malnutrition
Lockdown during the pandemic was a huge shock to the economy of the countries . During this time, the government has put initial emphasis to support poor, stabilize food prices, and to expand social protection programs . Some of the interventions implemented by the government, donors, and development partners are mentioned below:
Pakistan introduced an “Ehsaas program” which provided direct cash transfers to about 80 million people with a target of 12 million households and a budget of USD 900 million . The coverage was increased to an additional six million families during the pandemic, indicating the coverage of almost half of the Pakistan’s population . The government of Bangladesh also introduced several food and cash transfer programs . The prime minister of Bangladesh also provided one-time cash transfer as a gift of Eid-ul-Fitr worth BDT 2,500 to each of five million poor families, totaling BDT 12.5 billion .
Food Ration Distribution
The state government of India distributed staple food, vegetables, and fruits as take-home rations to poor and marginalized population . The governments of Rwanda, Uganda, and Botswana delivered food from house to house in urban areas, the Madagascar government placed markets where oil and rice were sold at half price, whereas the Sudan government sold food baskets at discounted rates . After the closure of schools in Lesotho and Liberia, school meals were replaced by take-home meals . The Ministry of Education of Libya and Congo, in collaboration with World Food Program (WFP), launched “school feeding at home” initiative, which provided take-home rations to the school children . The Ehsaas Nashonuma Programme in Pakistan also provided food to pregnant women and children in the most vulnerable settings with high rates of childhood stunting .
India introduced a support package named “Pradhan Mantri Garib Kalyan Yojana,” which helped to buffer the health and nutrition shocks during COVID-19 . This program provided insurance coverage of Indian Rupees 0.5 million to each health worker suffering from COVID-19. Rwanda revised its community-based health insurance scheme called “mutuelle de santé” by providing easy access to poor to become eligible for healthcare services . However, in Morocco, the households under the noncontributory health insurance (RAMED) received an one-time cash transfer worth USD 80–120 to support households .
Supporting the Unemployed
The Afghan government received a funding of USD 280 million for “COVID-19 Relief Effort for Afghan Communities and Households Project” . Under the Relief Effort for Afghan Communities and Households project, the program “Dastarkhan-e-Milli” aimed to cover 4.1 million households who had an income of USD 2 or less . The African government introduced a temporary Social Relief of Distress fund support program to assist unemployed people who were not covered by unemployment insurance or any other support program during COVID-19 . Some countries also created temporary work opportunities for the unemployed adults which included labor intensive public work .
The Pakistan government deferred the deadline of payment of utility bills, whereas the African government of 12 countries waived off the utility bills of mainly water and electricity to relief the partial burden from the shoulders of the poor people [81, 86]. Apart from the above listed interventions, the government of different countries also waived off rents, reduced fuel charges, relieved taxes, exempted VAT charges, and provided interest free loans to the community [55, 69, 81, 84].
COVID-19 fallout has gone far beyond a viral infection. It specifically has affected the lives of the most vulnerable population including children, pregnant and lactating women, and of people with a compromised immune system. Long-term programs that focus on the root causes of malnutrition should be encouraged, and both direct and indirect nutrition interventions across food, health, and social protection systems can be useful in catering malnutrition impacted by COVID-19. However, implementation of these interventions requires adequate coordination and a multi-sectoral approach to strengthen the efficient delivery and resilience of the families.
The government should adopt a wholesome strategy targeting sectors beyond health and nutrition including economy, agriculture, education, human rights, etc. The government should also conduct program evaluations to gauge its actual impact on health and nutrition of the population.
Measures taken to slow down the spread of COVID-19 has decreased the spread of virus but has also exposed the world to economic and food crises. Government, NGOs, donors, and UN agencies are working to strategize and prioritize investments for COVID-19, but at the same time, effective execution does require money, political will, great coordination, commitment, multi-sectoral collaboration, and international unity.
Conflict of Interest Statement
The writing of this article was supported by Nestlé Nutrition Institute and the authors declare no other conflicts of interest.
No internal or external funding was provided.
All the authors equally contributed to the writing of the manuscript.