Global Landscape of Nutrient Inadequacies in Toddlers and Young Children
Alison L. Eldridge Elizabeth A. Offord
Nestlé Research, Nestlé Institute of Health Sciences, Lausanne, Switzerland
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Abstract
Toddlers and young children need an adequate and diverse diet to provide all of the nutrients required for optimal growth and development. Unfortunately, inadequate intake of vitamins and minerals is still identified by the World Health Organization (WHO) as a major public health threat for young children. Organizations like the WHO and the World Bank focus primarily on iron, zinc, vitamin A, and iodine for children ≤5 years of age in low-income countries. In addition to the data from these organizations, individual-level food consumption surveys are needed to provide a fuller picture of food and nutrient intakes. Where studies are available, intakes of dietary fiber and vitamin D are generally below recommendations for toddlers and young children. Other nutrient gaps differ by country and are related to food availability and local dietary habits. For example, young children in the US regularly consume dairy products, and <10% fall below recommendations for calcium intake compared to 2- to 4-year-old toddlers in the Philippines where dairy food consumption is low, and 66–84% fall below calcium recommendations. Dietary intake studies can help to identify the foods and beverages most relevant to alleviate nutrient gaps and improve dietary intakes of toddlers and young children around the world.
© 2020 S. Karger AG, Basel
Introduction
Toddlers and young children need an adequate and diverse diet to provide all of the nutrients they require to support optimal growth and development. Unfortunately, undernutrition, growing rates of overweight and obesity, and inadequate intakes of vitamins and minerals are still identified as major public health threats for young children by the World Health Organization (WHO) [1]. For micronutrients, the WHO, UNICEF, and the World Bank focus primarily on iron, zinc, vitamin A, and iodine. Global monitoring shows that the combination of anemia rates, along with vitamin A deficiency and stunting, lead to an “alarmingly high” hidden hunger index in certain regions of the world, particularly sub-Saharan Africa and South Asia [2].
In addition to the global data from these organizations, individual-level food consumption surveys are needed to provide a fuller picture of food and nutrient intakes in different countries. However, these surveys are generally available in higher-income countries and are less common in low- and middle-income countries in regions such as Africa, Eastern Europe, and Southeast Asia [3]. Even among European countries with a food consumption survey, not all collect data on toddlers and young children [4]. National surveys in the US (National Health and Nutrition Examination Survey, NHANES) and Australia (National Nutrition and Physical Activity Survey, NNPAS) start only from the age of 2 years. Some national surveys also lack data on the full complement of nutrients required in the diet.
It is our aim, therefore, to evaluate what is known about the nutritional challenges and inadequacies facing toddlers across the world. With many sources of data, each one helps to build our knowledge by telling a different piece of the story. We will evaluate the information provided from each type of study and explore similarities and differences in the nutritional gaps of young children globally.
Monitoring Young Child Growth and Weight
The WHO, UNICEF, and the World Bank monitor several measures of growth and weight in children under 5 years of age globally [1, 5]. These measures help to identify and track problems of inadequate (wasting, stunting, and underweight) and excess nutrition (overweight and obesity), and because the measures are standardized, they also allow for comparisons across countries and over time. They are used by the WHO and UNICEF in collaboration with the Food and Agriculture Organization (FAO), the International Fund for Agricultural Development (IFAD), and the World Food Program (WFP) to monitor progress towards ending hunger, ensuring access to food, and eliminating all forms of malnutrition around the world [6].
Wasting refers to low weight for height, and usually results from recent and severe weight loss stemming from lack of food, diarrhea, or other infectious disease. Stunting is low height for age and is the result of chronic or recurring undernutrition associated with poverty, frequent illness, and inadequate feeding and care during early life. Underweight describes children who have a low weight for age. In addition to these issues of undernutrition, many children around the world are also facing excess body weight for height resulting in overweight or obesity due to overconsumption of energy relative to energy requirements.
Wasting affects 7.3% of the global young child population, or about 49.5 million children under the age of 5 years [5]. More than 60% of wasted children worldwide live in Southern or Southeastern Asia (61.2%) and another 28.3% live in Africa. Stunting currently affects 21.9% of children less than 5 years of age (149 million children), and while this is lower than the 32.5% in 2000 [5], progress is still too slow to reach global nutrition targets of 14.6% by 2025 [6]. Overweight is only reported for North America, Asia, Africa, and Latin America, where it affects 5.9% of young children, amounting to 40.1 million [5]. Rates of overweight in these regions have increased from 4.9 to 5.9% since 2000. Overweight children are found across all income classifications, though the highest proportions are among middle-income countries [5]. These data highlight that nutritional issues continue to affect our children (and families) globally; biggest problems of world hunger occur in sub-Saharan Africa and South Asia, and rates of overweight and obesity are growing in all regions and all age groups [6].
Micronutrient Deficiencies – The Big 4
Undernutrition is more than just an issue of energy intake – it also takes the form of inadequate intake of micronutrients (vitamins and minerals), leaving children at risk for deficiency diseases. The international agencies monitor certain vitamins and minerals in efforts to reduce the life-long consequences of low intakes of iron, zinc, vitamin A, and iodine [1]. Iron deficiency is the primary cause of anemia in young children, affecting both cognitive and physical development. Zinc intake is of concern, because deficiency limits childhood growth and decreases resistance to infection. Vitamin A intake and supplementation is monitored as vitamin A deficiency is the leading cause of childhood blindness globally. Iodine deficiency is the main cause of impaired cognitive development in children, and thus iodine deficiency and the impact of the universal salt iodization project are also scrutinized.
Prevalence of anemia, defined as hemoglobin <110 g/L at sea level, in children ≤5 years is highest in sub-Saharan Africa (59.9%) and South Asia (55.1%), whereas the rates are 15.3% in the European Union and 8.6% in North America [2]. The highest rates of vitamin A deficiency in young children are also found in sub-Saharan Africa and South Asia, where 60–70% are deficient [