Zinc deficiency is less prevalent, ranging from 15 to 50% across sub-Saharan Africa and South Asia, and is generally <5–10% for much of Europe, North America, Central Asia, and Oceania [2]. Universal salt iodization began in the early 1990s to reduce the global burden of iodine deficiency. This program has now been implemented in 120 countries, and as a result of these efforts, approximately 71% of households globally now use iodized salt [7], greatly reducing iodine deficiency.
Dietary Diversity, Feeding Frequency, and Minimum Acceptable Diet Scores
Several indicators have been created by the WHO to assess feeding practices for young children in regions at risk for inadequacies [8, 9]. A minimum dietary diversity score is calculated as a proxy measure for micronutrient adequacy of the diet. Minimum meal frequency is used to assess the likelihood of adequate energy intakes. These scores together are used to calculate a minimum acceptable diet score [10]. These indicators are collected as part of Demographic and Health Surveys (DHS), funded by the US Agency for International Development (USAID) and the Multiple Indicator Cluster Surveys (MICS) from UNICEF. Table 1 shows the scores for these indicators for children 12–23 months old across 7 UNICEF-defined regions [10].
Diet quality indicators show wide variability by geographic region and by country (Table 1). Overall, in the region of West and Central Africa, only 21.1% of children 12–23 months old reach minimum dietary diversity, and more than half of the countries in that region had less than 10% that met the minimum diversity score. In contrast, an average of 64.4% of children 12–23 months old in countries in Latin America and the Caribbean achieved the minimum diet diversity score. The average would have been >68% without Haiti, which suffered the aftermath from Hurricane Matthew during their most recent survey (2016–2017), resulting in only 19.8% achieving the minimum diet diversity score. The percentage of children 12–23 months of age achieving the minimum feeding frequency ranged from 41.3% in Eastern and Southern Africa to 74.8% in Eastern Europe and Central Asia. However, the overall scores for minimum acceptable diet were much lower, ranging from 11.2 in West and Central Africa to 50.1% in Latin America and the Caribbean. These assessments are qualitative, not quantitative, so specific estimates of energy and nutrient intakes are not possible with these instruments.
Table 1. Percentage of children 12–23 months of age achieving minimum dietary diversity, minimum feeding frequency, and minimum acceptable diet scores by UNICEF region
Dietary Intake Surveys
Detailed data on food and nutrient intakes and dietary patterns in young children require other methods and sources of data. National individual-level dietary intake surveys generally use multiple-day interviewer-assisted 24-h recalls or detailed diet diaries to estimate nutrient intakes and evaluate food patterns, but even with comprehensive surveys, not all include intakes of young children. For example, Huybrechts et al. [3] identified 39 national individual-level food consumption surveys globally, but less than half included children under the age of 5 years. Out of 18 countries with national surveys in Europe (2000–2016), only two-thirds reported energy and nutrient intakes for children ≤5 years [4].
Other large-scale surveys, such as the Feeding Infants and Toddlers Study (FITS) [11] and the South East Asian Nutrition Survey (SEANUTS) [12], include detailed dietary assessments of young children. FITS is a cross-sectional study in the US started in 2002, with subsequent surveys collected in 2008 and 2016. FITS provides comprehensive dietary intake data for infants, toddlers, and young children from birth up to the age of 4 years. A similar approach was used in China for the Maternal Infant Nutrition Growth (MING) study [13, 14]. FITS has also been used as a model to analyze national survey data on toddlers and young children from other countries, including Mexico [15, 16], Russia [17], and the Philippines [18]. SEANUTS was conducted in Indonesia, Malaysia, Thailand, and Vietnam, and included data from children 6 months to 12 years of age; data from Indonesia are included here as an example [19]. Survey data from a multicenter study in 9 cities in Brazil [20] and nationwide samples of German toddlers [21, 22] are also included for comparison purposes.
Fig. 1. Macronutrient distribution in toddlers and young children in selected countries.
When looking at the detailed dietary intake studies, we find wide ranges in energy intakes for 2- to 3-year-old children, with lower intakes in the Philippines (839 kcal/day) [18] and Indonesia (965 kcal/day) [19], and higher intakes in Brazil (1,650 kcal/day) [20], the USA (1,397 kcal/day) [23], and Mexico (1,367 kcal/day) [16]. Energy intakes were intermediate in children 2–3 years old from Russia (1,243 kcal/day) [17], Germany (1,075 kcal/day) [21], and China (1,189 kcal/day) [13]. Energy intakes corresponded to higher rates of stunting in the Philippines, and higher rates of overweight and obesity in Brazil, North America, and Europe [2]. The distribution of energy from protein, fat, and carbohydrates also differs by country, with higher carbohydrate and lower fat intakes in Southeast Asia (Fig. 1).
Dietary fiber and vitamin D intakes are generally below recommendations for toddlers and young children, though vitamin D is not reported for every country (Table 2). Other nutrient gaps differ by country and are related to food availability and local dietary habits. For example, US children 2–4 years old regularly consume dairy products [24], and <10% (6.4% of children 24–35 months old