The Changing Landscape of Children's Diet and Nutrition: New Threats, New Opportunities
The last 40 years have witnessed a significant improvement in the status of childhood undernutrition, with reductions in stunting and wasting. Unfortunately, this progress has been offset by a rise in childhood obesity. Rising obesity rates were first observed in older children, but this age of onset has rapidly decreased such that obesity has now overtaken wasting as a leading risk factor for mortality. Malnutrition now appears in several guises: from stunting and wasting to overweight and obesity. The root cause has not changed: poor food choices, inadequate eating patterns which start early in life, and inefficient food systems remain the key drivers of malnutrition. This is especially prevalent in low-income communities, where there is an overlap in the presence of malnutrition in its various forms: obesity, wasting, stunting, and micronutrient deficiencies.
The drivers of poor health and mortality of the past, such as infectious diseases, have been replaced by an epidemic of noncommunicable diseases (NCDs), most of which are related to poor nutrition, often starting in childhood. NCDs, such as cardiovascular diseases, diabetes, cancer, and chronic respiratory diseases, have a dramatic impact on healthcare costs and are collectively responsible for almost 70% of all deaths worldwide. Of these, nearly three-quarters of all NCD deaths occur in low- to middle-income countries. Climate change and the recent pandemic have severely impacted food production and security and are important threats that shape early food choices and infant feeding practices.
The international community has endorsed comprehensive plans with the aim to eliminate all forms of malnutrition, reduce anemia in women and children, and ameliorate the burden of diet-related NCDs in all age groups. Although some progress has been made, many key objectives are still far from reached. Poor diets, reflected by low consumption of fruits and vegetables alongside rising consumption of red meat and sugar-sweetened beverages, have not improved over the last decade. Finally, no region in the world is on track towards meeting the Sustainable Development Goals set by the UN to limit the health and environmental burdens related to diets and the food system. Major changes to food systems and participation of all sectors will be needed to reverse these trends.
Swinburn BA, Kraak VI, Allender S, Atkins VJ, Baker PI, Bogard JR, et al. The global syndemic of obesity, undernutrition, and climate change: the Lancet Commission report. Lancet. 2019;393(10173):791-846.
• Despite progress in child wasting and stunting these persist, and micronutrient deficiencies remain high. Overweight and obesity prevalence continue rising and will soon overtake moderate underweight and wasting prevalence in children.
• The diets of most children in most countries are inadequate and reflect global disparities.
• Most children with obesity, wasting, stunting, and micronutrient deficiencies live in lower income countries and in lower income communities within any country.
• Nutrition-related risks are the leading cause of global mortality and disability.
• Climate change remains a major risk to food systems, while food production remains the greatest contributor to climate change.
• Major changes in food systems and participation of all sectors will be needed to reverse these trends.
Children • Nutrition • Malnutrition • Obesity • Diets • Climate change • Pandemic
Background: Over the last 30-40 years, we have seen an im-provement in global child undernutrition, with major reduc-tions in wasting and stunting. Meanwhile, childhood obesity has dramatically increased, initially in high-income popula-tions and subsequently in the more economically vulnerable. These trends are related to significant changes in diet and external factors, including new environmental threats. Sum-mary: Obesity rates first increased in older children, then gradually in infants. And in the next couple of years, there will be more overweight and obese than moderately or severely underweight children in the world. The changes in childhood nutritional landscape are a result of poor diets. Today, almost 50% of the world's population consumes either too many or too few calories. Dietary disparities between countries result in disparities of under- and overnutrition and impact the global health landscape. Most children with obesity, wasting, and micronutrient deficiencies live in lower income countries and in lower income families within any country. High energy-low nutrient diets are contributing to the increase in non-communicable diseases, which will manifest later in this gen-eration of children. In 1990, child wasting was the #1 leading risk factor for mortality for all ages, and high BMI was #16; today, they are #11 and #5, respectively. COVID-19 and cli-mate change are new major threats to global nutrition. Cur-rent and future efforts to improve the state of child nutrition require multisectoral approaches to reprioritize actions which address current trends and emerging threats.
The nutrition of children is a major marker and determinant of the health, wellbeing, and productivity of individuals and the progress of society. The need for “early intervention" in child nutrition gathered increasing attention in the last half-century: first, with a focus on increasing child survival, then with greater emphasis on correcting nutritional deficits, and only in the last 3 decades, addressing both deficits and dietary ex-cesses. This was partly driven by the increased scientific un-derstanding that nutrition in early life is a determinant of long-term adult health. Thus, the challenges, the needs, and the focus have evolved with changing times. This paper reviews the changes in the landscape of child nutrition over the last several decades, the state and changes of their diets, the evo-lution of the health consequences resulting from these changes, as well as in the threats - old and new - hindering our progress. Finally, it briefly discusses the opportunities we have and the areas needing action or improvement to better the health and nutrition of children.
The Changing Landscape of Child Nutrition
The survival and health of children have been a key marker and driver of global development of human society for thou-sands of years. In just the last 200 years, we have seen extraordinary changes and accelerations in these markers. Around 40-50% of children did not survive to age 5 years in the 1800s. In 1900, this figure was 36%; in 2017, it is 4%. In many ways, it can be argued now is the best time for children to be alive [1, 2]. However, despite these improvements, this still means that, on average, 15,000 children younger than 5 years die each day . Half of these deaths are attributable to undernutrition, particularly wasting or thinness, which has been the most persistent visible and measurable underlying factor in this mortality .
Severe wasting is a marker of nutritional deficits, often as-sociated with increased infectious morbidity and mortality. Stunting is a marker of children's poor somatic and cognitive development, contributing to disabilities and low productivity. These “anthropometrically-defined" forms of malnutrition are frequently accompanied by micronutrient deficiencies, typi-cally less visible, and harder to measure. These deficiencies, termed by some “hidden hunger," in themselves, may be a greater contributor to disabilities than stunting or wasting alone . The prevalence of all these forms of undernutrition has decreased significantly in the last few decades, and we have seen the emergence of overnutrition: overweight and obesity in children. Over the last 4 decades, obesity has in-creased in every country in the world, and may very soon overtake undernutrition in prevalence, and become the major contributor to chronic disease and the global burden of dis-ease . The world simultaneously bears today a burden of undernutrition (caused by lack of macro and/or micronutri-ents) and overnutrition (primarily caused by an excess in en-ergy intake vs. expended).
In addition, these nutritional disturbances are also chang-ing in where they manifest. The distribution of different forms of malnutrition and their rate of change is also changing rap-idly, leading to rapid situations of “transition" within given populations and geographies, requiring rapid adaptation of countries to address them. Not only is the prevalence of dif-ferent forms of malnutrition changing, but it is doing so in the same place. More than one form of malnutrition can coexist within the same country, the same city or community, the same household, and even the same child. For the purposes of this review, we will adopt the more broad UNICEF definition of “child" as “any person under the age of 18" found in https:// www.unicef.org/child-rights-convention/convention-text- childrens-version. Examining the situation in some more detail over the last few decades:
For Children under 5 Years of Age
Globally, the prevalence of stunting and wasting has mark-edly declined to their lowest levels ever. From 2000 to 2015, the global prevalence of low birth weight decreased at an average rate of 1.23% annually, from 17.5% to 14.6% . For children under 5 years of age, from 1990 to 2010, the global estimated prevalence of stunting decreased from 39.7% to 26.7%. From 2000 to 2020, the prevalence of stunting dropped from 33.1% to 22% in children below 5 years of age. Today, 45.4 million children under 5, or 6.7% have wasting , down from 52 million children or 8% in 2011, and an estimated 58 million in 1990 . While today's prevalences are the lowest ever estimated, this represents 149.2 million children under 5 years of age who are stunted and 45.4 million who are wasted . By 2025, the number of stunted children is estimated to be 131 million, while the prevalence of wasting will remain well above 5% .
The change on the other end of the nutrition spectrum has also been considerable. For children 2-4 years of age, be-tween 1980 and 2015, the global prevalence of obesity almost doubled, from 3.9% to 7.2% in boys and 3.7 to 6.4% in girls. It was initially driven by increases in high-income countries, where it has recently slowed down, while the rates have increased in countries of lower incomes . Looking at a more recent timeframe, from 2000 to 2020, global obesity rates for children under 5 years of age increased only slightly, from 5.4% to 5.7% or 33.3 to 38.9 million children, with the fastest growing prevalence in Asia and Africa. Today, the global prevalence of wasting in children under 5 years of age stands at 6.7% and of overweight very close at 5.7% . The Brookings Institution estimates that by 2030, 90 million children aged 2-4 years, equal to 22% of the world's total, will be overweight .
For Children 5-19 Years of Age
We only recently have good global estimations of nutritional status in this age-group. Regarding thinness, expressed as body mass index over the last 30 years, mean BMI trends have shown increases in almost every country, including most countries in Africa. It is estimated that the absolute number of underweight children (low weight for age) peaked around the year 2000 and has since been decreasing . Southeast Asia and sub-Saharan Africa have the greatest persistent prevalence of children with low BMI. The trends are also improving as related to age. In most countries, the prevalence of thinness decreases as children enter adolescence, and in some low- and middle-income countries (LMICs), it disappears by the age of 19 years . Looking at a more recent time frame, from 2010 to 2020, the global prevalence of thinness among children and adolescents has declined more modestly, from 12.8% to 10.9% in boys and 9.6% to 8.9% in girls (aged 5-9 years) and from 13.4% to 12.3% in male adolescents and from 8.1% to 7.9% in female adolescents (aged 10-19 years) . Data on stunting in older children are more limited. Surveys including children 12-15 years of age from 57 LMICs between 2003 and 2013 showed a global prevalence of stunting of 10% . Stunting in adolescent girls (15-19 years) in LMICs varies significantly, from 52% in Guatemala and 44% in Bangladesh to 6% in Brazil . Nevertheless, in the last 30 years, there has been a significant gain in height for boys and girls in most countries. In the largest recent global studies, most countries showed that height was at or above the WHO median for chil-dren after 5 years of age, with girls doing better than boys [12, 13].
From 1975 to 2016, the global prevalence of obesity in 5- to 19-year-olds increased eightfold, from 0.7% to 5.6% in girls, and from 0.9% to 7.8% in boys . This translates to an increase from 5 to 50 million girls and from 6 million to 74 million boys over this time. However, since about 2000, the rate of increase has begun to slow down in high-income countries and recently plateaued, especially in North America, northwestern Europe, and “high-income English-speaking" countries. Meanwhile, the increase has averaged 400% per decade in southern African countries, albeit starting from a low baseline. While prevalence remains higher in higher income countries, in absolute numbers, the great majority of overweight and obese girls and boys are in LMICs . In round terms, from 2000 to 2016, the proportion of overweight 5- to 19-year-old children rose from 1 in 10 to almost 1 in 5 . Given these trends, a 2017 estimate suggests that in just the next couple of years, if post-2000 trends continue, the world may swing to having more obese than moderate and severely underweight children and adolescents . The potential effect of the coronavirus pandemic on these figures is yet to be seen and is discussed below.
The state of micronutrient adequacy still suffers from an even greater lack of adequate and reliable population-based data on biomarkers of micronutrient status, hindering moni-toring of micronutrient deficiencies. The information for most micronutrient status biomarkers is scarce and often outdated. Nevertheless, deficiencies of iron, vitamin A, vitamin D, zinc, iodine, and folate remain very high globally. The World Health Organization (WHO) estimates that 25% of school-age children (around 305 million children) have anemia and that 50% of it is primarily associated with iron deficiency. Prevalence of anemia among girls and women of reproductive age remains a major problem, with little or no progress in the last 10 years .
For all ages, and in all settings, all forms of malnutrition coex-ist, increasing disparities between nations. It is common to find under- and overnutrition coexisting in the same country, the same community, the same household, even in the same child. Micronutrient deficiencies are not uncommon in stunted or obese children. The trend changes mentioned above have led to increasing disparities in the burden of malnutrition. In 2020, 94% of children under 5 years of age with stunting, 97% of those with wasting, and 75% of those who are over-weight lived in Asia and Africa . Disparities are also evident in high-income countries. For example, in the USA, 16.7% of Hispanic 2- to 5-year-olds were obese, compared with a pop-ulation average of 8.4% . Thus, most LMICs confront all forms of malnutrition, and independent of the country, most children with all forms of malnutrition are from the most so- cio-economically disadvantaged communities.
These changes in children's nutritional situation are not only reflected in different prevalence but in the degree of the differences of nutrition markers between countries. The dif-ference in BMI between countries with the highest mean BMI (e.g., Pacific Island countries, the USA, Chile, South Africa) and lowest mean BMI (e.g., India, Bangladesh, Ethiopia, and Chad) was 9-10 kg/m2; that is a difference of more than two standard deviations. The estimated difference in height of 19-year- olds between countries with the tallest populations (e.g., the Netherlands, Denmark) and the shortest (e.g., Timor-Leste, Laos, Guatemala, Bangladesh) was 20 cm [12, 13].
In summary, the global nutritional landscape is changing and changing faster than at any other documented time, par-ticularly in children. Today, all forms of malnutrition coexist in all countries and settings. The last 30 years alone show sig-nificant decreases in wasting and stunting and rise of over-weight and obesity, which increasingly affects younger chil-dren. The rise in obesity has been dramatic and has gradually shifted from higher to lower income countries and to lower income groups within countries. If current trends continue, in the next couple of years, there will be more overweight and obese children than moderately or severe underweight chil-dren . But, already today, the gaps and disparities on the burden of global malnutrition are very large. Most children with obesity, wasting, stunting, and nutrient deficiencies live in the most vulnerable countries or communities within a country.
The Changing Diets of Children
Nutritional status is dependent on dietary intake, and today, this intake is globally imbalanced. It is estimated that 48% of the global population eats too many or too few calories, lead-ing to global population rates of overweight (26%), obesity (13%), and underweight (9%) .
The global dietary scenarios are also changing. Breast-feeding, adequate complementary feeding, and eventually the family diet are all part of the dietary determinants of the nutritional status of children discussed above. In the first months of life, exclusive breastfeeding remains the ideal diet and form of feeding for infants. Here, there has also been some progress. From 2000 to 2015, the global prevalence of early exclusive breastfeeding increased from 36% to 43% . Globally, estimates of exclusive breastfeeding showed some progress, with 41.6% of infants under 6 months being exclusively breastfed in 2018, compared with 37% in 2012 . Breastfeeding duration is still shorter than desirable, particularly in high-income countries. More importantly, more than 60% of infants in LMICs receive earlier than recommended complementary feedings or inadequate breastmilk substitutes, which, in unsanitary conditions contribute to undernutrition and disease . Over the last 20 years, infant formula consumption has increased in high- and middle-income countries, while remaining low in low-income countries, particularly sub-Saharan Africa and South Asia. Animal milk consumption under 6 months has also decreased significantly in LMICs .
At a global level, for all ages, the Global Nutrition Report in 2021 indicates that diets are far from being healthy and have not improved over the last decade. Assessing diets based on WHO-UNICEF guidelines, fruit and vegetable intake is still about 50% below the recommended five servings per day, and legume and nuts intakes are each more than two-thirds below recommended (two servings per day). On the other hand, red and processed meat intake is on the rise, close to five times the recommended high level (one serving per week). Similarly, the intake of sugar-sweetened beverages is increasing globally. The report concludes that despite variation between regions, no region meets recommendations for healthy diets. Only milk and fish intakes are within recommended ranges .
Dietary data for infants and young children have histori-cally been sparse and difficult to obtain. Global and regional complementary feeding is particularly scant. A recent UNICEF report, based on a large number of representative dietary surveys in 135 countries and territories, reported on the state and progress of the diet in infants under 2 years of age in LMICs. In this report, about two-thirds of children 12-23 months in these LMICs were still being breastfed on a given day. Twentyseven percent of children aged 6-8 months were still not fed any solid, semi-solid foods, although this was a small improvement from 33% in 2010. In children between 6 and 23 months, the progress over the last 10 years (2010-2020) has been minimal. The percentage of children consuming eggs, fish, and/or meat on a given day was 32% and 36% and vegetables and/or fruit 48% and 53% in 2010 and 2020, respectively. The report also noted “unhealthy processed foods and drinks are widely accessible and heavily marketed” in a select group of countries studied .
The progress in trends has been marginal. The percentage of children in LMICs fed the minimum recommended number of meals or snacks throughout the day was 54%, a 3% increase from 2010. Twenty-four percent of children are consuming a minimally diverse diet (receiving 5 of 8 recommended food groups) - compared to 21% 10 years ago. Of 50 countries assessed, significant improvements in diet diversity were reported in 21 countries, and 10 countries had a substantial drop in the percentage of children consuming a minimally diverse diet. In summary, the report concluded that diet quality in LMICs had improved very marginally over the past 10 years. More detailed global estimates of energy and specific nutrient intake are still needed .
In higher income countries there have been few, but more in-depth, nutrition surveys. In the USA, the Feeding Infants and Toddlers Study, a large cross-sectional nationally repre-sentative survey, finds patterns similarly replicated for other higher income countries. It shows improvements in breast-feeding initiation (above 80%) but low exclusivity and duration (only 15% at 4-6 months of age). On a given day, more than 20% of infants below 2 years of age will not consume a serving of fruit or vegetables on a given day, while approximately half consume fruit juice and one-quarter to one-third consume sugar-sweetened beverages . The mean reported intake of energy for infants 0-6 and 6-12 months of age, sexes combined, was about 25% higher than the estimated energy requirements for the children in the 50th percentile for these two age ranges. For 12- to 24-month-olds, it was 30% higher .
On the other hand, except for persistent concerns of iron adequacy, micronutrient intake in infants is largely adequate. Preschoolers have a high intake of sodium and saturated fat and lower than desired intakes of vitamins. High intakes of retinol, zinc, and folic acid are common [22, 23]. Estimates in Mexico, as an example, show that 50% of children 6-48 months of age did not consume fruits, and 80% did not con-sume any vegetables on a given day. However, 80% con-sumed sugar-sweetened beverages after 12 months. A total of 61% of infants 6-12 months old did not meet the estimated requirement for iron . Surveys in urban China also show low breastfeeding rates (47% after 6 months), with increasing consumption of infant formulas and fortified milks. Similarly, about 50% of infants did not consume any fruits or vegetables, and 38% of toddlers did not consume any fruits on a given day .
In summary, as expected, dietary changes over time have correlated with changes in nutritional status. In low-income scenarios, energy intake has improved, but high-quality pro-tein and micronutrient intake improvement have been mar-ginal. In middle-income groups, excesses in energy-dense but nutrient-poor diets have increased. Diet gaps remain or have widened. One-quarter of children in some poorer coun-tries do not receive solid food at 6-8 months, while the aver-age energy intake of infants is 25% higher than requirement in some richer countries. Regardless of the region, diet diversity remains low and with no improvements. Most children in the world are not consuming fruits and vegetables most days [21-23].
Thus, most countries are going through a rapid transition phase, requiring rapid adaptation to deal with persistent un-dernutrition and rising obesity. Such rapid changes and transitions will require understanding and addressing multiple factors driving the change and their impacts. These include, among many, economic and social changes, education, cul-tural barriers, and especially changes in our food systems .
The Changes in Health Consequences of Child Nutrition
The nutritional consequences of inadequate diets in early life are clear: undernutrition and overnutrition lead to specific short-term effects on morbidity and mortality. However, the impact of nutrition on child development has long-term health consequences into adulthood and remains critical for the well-being and development of individuals and society. The changes in diet and nutritional landscape in children have therefore also brought about changes in the health landscape of the global population.
It is beyond the focus of this paper to discuss the growing concept of the developmental origins of health and disease and the many mechanisms of early nutrition programming of health. But, suffice it to say that both under- and overnutrition in early life can lead to permanent structural and functional changes that result in chronic disease [27, 28]. The causes of poor health and mortality of the past, particularly infectious diseases, have been replaced by an epidemic of noncommu-nicable diseases (NCDs). Cardiovascular diseases, diabetes, cancer, and chronic respiratory diseases, leading to disabilities and premature death, dramatically impact healthcare costs and the economic burden of countries. NCDs are collectively responsible for almost 70% of all deaths worldwide. Nearly three-quarters of all NCD deaths occur in LMICs countries . The changes in diet and nutrition, particularly in early life, are the most critical underlying and mechanistic factors for the development of chronic NCDs. Therefore, early life, par-ticularly gestation through the first 2 years (the first 1,000 days) and other periods of dynamic changes in growth and development (such as the transition to middle childhood and adolescence) are particular “windows of opportunity” in nutri-tion that are relevant to long term health, productivity, and well-being .
The Global Burden of Disease (GBD - a large global re-search consortium that tracks worldwide death and disability) reported in 2019 the ten highest risks factors associated with the highest number of deaths worldwide. Of these, six factors are nutrition-related: high plasma glucose, high blood pressure, high BMI, high LDL cholesterol, child and maternal malnutrition, and “dietary risks” (e.g., low consumption of fruit and vegetables, high consumption of sugar-sweetened beverages, high salt intake). The other four include tobacco and alcohol use, air pollution, and kidney dysfunction. Comparing the GBD mortality trends from 1990 to 2019, the most significant declines in associated deaths were linked to improvements in child growth failure, household air pollution, unsafe water, and sanitation. The largest global increases in mortality were associated with high fasting plasma glucose, and high BMI. When assessing disabilities (measured in disability-adjusted life-years, DALYs), the GBD estimated that in 1990, child wasting, low birth weight, and prematurity were the number 1st, 2nd, and 3rd global causes of DALYs, considering all ages. Today, they are the 11th, 4th, and 6th, respectively, in large part related to the significant reductions in child mortality as a result of immunization, primary health care and living standards since 1990. On the flipside, in 1990, high BMI, high fasting glucose, and high cholesterol were the 16th, 11th, and 18th cause of disability. Today, they rank 5th, 3rd, and 8th. So, today, considering all age-groups, overnutrition is the highest contributor to disability, and high BMI is, by far, the fastest-growing risk for disability worldwide.
For children, however, despite improvements, malnutrition persists. For children aged 0-9 years, the three leading risk factors for attributable DALYs were all related to undernu-trition, including child wasting and micronutrient deficiencies . In summary, malnutrition in all its forms, which includes obesity, undernutrition, and dietary risks for NCDs, is already the biggest cause by far of health loss globally.
The Emerging Threats to Child Nutrition
Diets and nutritional outcomes in children are determined by parents' and caregivers' food choices and feeding practices and eventually are determined by individual dietary behaviors. These are influenced by multiple external factors that shape these behaviors - not discussed here - but ultimately, they require food security, access, and affordability of foods sufficient to fulfill an adequate diet. Agriculture and production, distribution, processing, marketing, retail sales, preparation, consumption, and waste disposal or recirculation are all critical environmental components of food systems - all of which have dramatically changed in recent times - determine food security and the ultimate intake of nutrients . Of the many threats which directly affect global nutrition and health, climate change and global pandemics are today of particular relevance.
Food Systems and Climate Change
Climate change per se has direct effects on health, related to extreme weather, and to the droughts and flooding which impact food-borne and other infectious diseases. However, the impact on food insecurity brought about by crop failures, reduced food production, extreme weather events, and con-sequent undernutrition are potentially devastating. In parallel, countries transitioning transitions from lower to higher in-comes are experiencing rapid urbanization and increased motorized transportation, leading to lower physical activity and greater obesity rates. The United Nations estimates that in 2007, for the first time in human history, more people in the world lived in urban rather than in rural areas. Today, over 55% of humans live in cities. By 2050, it is projected that less than one-third of the world will live in rural areas . Conversely, food systems are a major contributor to climate change. It is estimated they account for one-third of all greenhouse gas emissions. Livestock alone account for 12-19% of greenhouse gas emissions. Different foods also have different effects. Meat and dairy products require more resources and generate larger emissions than plant-based foods. Socioeconomic improvements have led to dietary patterns of populations, which include increasing consumption of meat, dairy, and other processed foods, whose production is associated with high greenhouse-gas emissions. Preserved, frozen, and transported fruits and vegetables increase greenhouse gasses, and energy required for collection and management of food waste compounds the problem [33, 34].
Through multiple simultaneous and interacting health risks, climate change threatens to reverse years of progress in public health and sustainable development. More critically, it further increases the differences and disparities since LMICs are likely to be more affected by climate change, while high- income countries are greater contributors to greenhouse emissions. Given the many interwoven drivers and multiple components of food systems, better approaches to address multiple sectors in society are needed [35-37].
In summary, nutrition, health, and climate change are inti-mately linked in a complex interaction, recently termed “The Global Syndemic” of obesity, undernutrition, and climate change. The Lancet Commission publishing this report  called for collective multisectoral actions to address this “syn- demic” and “stimulate the reorientation of human systems to promote health, equity, economic prosperity, and sustainabil-ity” and offered specific broad recommendations to address the drivers of this syndemic [33, 34, 36].
The COVID Pandemic
In November of 2019, after China reported the first cases of the SARS-CoV-2 virus, which causes coronavirus disease (COVID-19); the infection spread globally, causing more than 5 million deaths, and this count continues to rise in 2022. De-spite extraordinary progress in biotechnology and vaccinol- ogy, which developed effective vaccines and therapeutic ap-proaches in record time, the unequal distribution of these and the unequal pre-pandemic vulnerability of underserved pop-ulations to disease and its consequences were put in evi-dence. COVID-19 is having immediate and likely long-lasting repercussions on global nutrition.
The pandemic has brought about a significant drop in ag-ricultural production and supply chains. It is impacting food processing, transportation, travel, supply chains and trade re-strictions, loss of employment, reduced incomes, and higher prices - all of which will affect the food availability and un-doubtedly the nutrition of individuals, particularly children. Estimates from The World Food Program suggest that the number of people facing acute food insecurity was expected to rise from 135 in 2019 to 265 million in 2020 . UNICEF estimated a 30% overall reduction in coverage of essential nutrition services coverage, which could reach a 75-100% reduction in some countries facing humanitarian crises. Esti-mates in 2020 suggest there could be a 14% increase in the prevalence of moderate or severe wasting among children under 5 years of age, a major setback in the progress made until recently [39, 40]. Exact figures will confirm these projec-tions soon. The Global Nutrition Report in 2021  stressed that additional investments will be needed to meet the global nutrition targets set by WHO for 2025 to overcome the effects of the pandemic.
On the other hand, we may see the opposite effect in some populations. Poor diet quality of children, with excess energy and low nutrient density, may increase and be compounded by decreased physical activity due to changes in schooling, inactivity from lockdowns and quarantines, potentially increasing obesity rates in middle-and high-income settings, especially among their vulnerable groups . Increases in intake of less nutrient-dense foods, increased snacking, and greater inactivity have been reported in surveys in Europe  and increased rates of weight gain among school-age children in the USA . The degree of infectivity of the virus has fortunately been lower in children; however, it is clear the social and economic consequences of the pandemic will increase their nutrition and other health-related risks, especially in the most vulnerable populations . We will need to wait to assess the full effect of the pandemic, but it is clear that, at least in some populations, both undernutrition and overnutrition will increase.
In the last 2 decades, the international community has in-creased its commitment to nutrition. In 2012 the World Health Assembly (WHA) endorsed a comprehensive plan for mater-nal, infant, and young child nutrition, specifying nutrition tar-gets for 2025 [45, 46]. In 2014, the Second International Con-ference on Nutrition (ICN2), the Food and Agriculture Orga-nization of the United Nations (FAO) endorsed documents committing world leaders to establish national policies aimed at “eliminating malnutrition in all its forms” and transforming food systems to make nutritious diets available to all . In 2015, the United Nations adopted the 2030 Agenda for Sus-tainable Development and its sustainable development goals, which included the commitment to “end hunger, achieve food security and improved nutrition, and promote sustainable agriculture.” The UN proclaimed the years 2016-2025 as the United Nations Decade of Action on Nutrition and called for an effort by all relevant stakeholders and identified specific goals to address hunger, all forms of malnutrition, particularly in children under 5 years of age, and anemia in women and children and reduce the burden of diet-related NCDs in all age-groups . That same year, the WHA welcomed the report of the Commission on Ending Childhood Obesity and its six recommendations to address the obesogenic environment and critical periods in the life course to tackle childhood obesity .
Undoubtedly, progress has been made with these and many other initiatives, but the task is far from completed. In 2021, the Global Nutrition Report assessed that of 194 coun-tries, 105 are on track to meet the target for childhood over-weight, 27% are on track to meet stunting, and 29% to meet wasting targets. The reduction of anemia in women of repro-ductive age has hardly improved. Hardly any country is on track to meet their targets for overall rates of obesity and diabetes or reducing salt intake. Poor dietary intake world-wide, driven by low consumption of fruits and vegetables, and rising consumption of red meat and sugar-sweetened beverages have not improved over the last decade. Finally, no region in the world is on course to meet the sustainable development goals set by the UN to limit the health and envi-ronmental burdens related to diets and the food system. For example, all regions have diets that, if globally adopted, cre-ate impacts that are above levels necessary to limit global warming .
As discussed previously, better integration of actions that involve the multiple relevant systems and sectors related to nutrition will be needed. In 2021, the UN Food Systems Summit highlighted the need to accelerate the transformation of food systems to enable better diets and improve nutrition. Very recently, UNICEF published its “Nutrition Strategy 2020-2030” . This plan “intends to strengthen five key systems - food, health, water and sanitation, education, and social protection - to deliver nutritious diets, essential nutrition services, and positive nutrition practices for children, adolescents, and women” and is a clear step in the right direction, to help countries better integrate their efforts and priorities. However, this ambition requires resources, which have been even more constrained due to the COVID-19 pandemic. The same year, the Tokyo Nutrition for Growth Summit  announced financial and policy commitments to chart the path toward 2030. The summit laid a roadmap and sought “encouraging governments, business, donors, and other development partners to make tangible data-driven financial, policy, programmatic, or impact related commitments, to accelerate efforts toward stronger nutrition action spanning food, health, and social protection systems.”
In just the last 30-40 years of the modern era, we recognized the importance of child nutrition and health as determining factors in the development of its communities, countries, and society, and took action. The scientific understanding of the effects and mechanisms of nutrition in early life and long-term health has exploded. The economic argument for investing in children's health and education is irrefutable and is characterized by high benefit-cost ratios [1, 30]. As stated in a recent World Bank report, as opposed to other investment priorities, the returns on early life nutrition are durable, inalienable, and portable. They are “durable because investments made during the critical 1,000-day window of opportunity last a lifetime without ever needing to be replenished and inalienable and portable because they belong to that child no matter what and wherever she or he goes” .
During this time, remarkable progress has been made in improving child survival and decreasing undernutrition. Si-multaneously, we were faced with the need to continue to improve undernutrition while countering the explosive rise of overweight and obesity. This has led to the co-existence of malnutrition of all types and its health consequences, includ-ing the epidemic of chronic NCDs. All forms of malnutrition and their health consequences are disproportionately im-pacting - in prevalence and degree - the more vulnerable populations and communities, independent of countries or regions. Finally, new threats are hindering progress. Climate change - partly the result of food systems that have positively increased agricultural production - is threatening global health and the sustainability of these same food systems. The threat of infectious pandemics such as COVID-19 will remain, so it will be crucial to learn how to prevent and manage these in the future. Diet and nutrition are the foundation for the long-term health and well-being of societies. It will thus take a whole of society approach and collaboration of all to adapt. We need to correct course where needed, and to manage threats as they arise, to create a virtuous circle where human food production and consumption meet on a healthy, sus-tainable plane.
Conflict of Interest Statement
J. Saavedra is the former Chief Medical Officer of Nestlé Nutrition and Chairman of the board of the Nestlé Nutrition Institute and currently is the Scientific Board Member for Scaled Microbiomics. The writing of this article was supported by Nestlé Nutrition Institute.
The content of this paper is the author's sole responsibility. All relevant sources are appropriately attributed.
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