Maternal and child undernutrition remain pervasive and damaging conditions in low-income and middle-income countries. A framework developed by UNICEF recognises the basic and underlying causes of undernutrition, including the environmental, economic, and sociopolitical contextual factors, with poverty having a central role (figure 1). Although addressing general deprivation and inequity would result in substantial reductions in undernutrition1 and should be a global priority, major reductions in undernutrition can also be made through programmatic health and nutrition interventions. This paper is the first in a Series of five papers that focus on the disease burden attributable to undernutrition and the interventions affecting household food availability and use, maternal and child care, and control of infectious diseases. The first two papers quantify the prevalence of maternal and child undernutrition and consider the short-term consequences in terms of deaths and disease burden, as measured by disability-adjusted life-years (DALYs). They also discuss the long-term educational and economic effects and associations with adult chronic diseases, particularly as countries go through the demographic, epidemiological, and nutritional transitions.2, 3, 4, 5, 6 The third paper estimates the potential benefits of implementing health and nutrition interventions that current evidence indicates are effective and applicable in low-income and middle-income countries. The final two papers consider the current state of such interventions and how they could be implemented fully through actions at national and global levels.
Undernutrition encompasses stunting, wasting, and deficiencies of essential vitamins and minerals (collectively referred to as micronutrients) as one form of the condition known as malnutrition, with obesity or over-consumption of specific nutrients as another form. The term hunger, which literally describes a feeling of discomfort from not eating, has also been used to describe undernutrition, especially in reference to food insecurity, wherein people do not have “physical and economic access to sufficient, safe, nutritious, and culturally acceptable food to meet their dietary needs”.7, 8 Undernutrition is an important determinant of maternal and child health.9, 10, 11, 12
Key messages
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Maternal and child undernutrition is the underlying cause of 3·5 million deaths, 35% of the disease burden in children younger than 5 years and 11% of total global DALYs
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The number of global deaths and DALYs in children less than 5 years old attributed to stunting, severe wasting, and intrauterine growth restriction constitutes the largest percentage of any risk factor in this age group
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Vitamin A and zinc deficiencies have by far the largest remaining disease burden among the micronutrients considered
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Iodine and iron deficiencies have small disease burdens, partly because of intervention programmes, but sustained effort is needed to further reduce their burden
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Suboptimum breastfeeding, especially non-exclusive breastfeeding in the first 6 months of life, results in 1·4 million deaths and 10% of disease burden in children younger than 5 years
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Maternal short stature and iron deficiency anaemia increase the risk of death of the mother at delivery, accounting for at least 20% of maternal mortality
The Millennium Development Goals (MDGs) state as the first goal “to halve between 1990 and 2015 the proportion of people who suffer from hunger.”7 One indicator to monitor progress for this target is the proportion of children who are underweight—ie, low weight compared with that expected for a well-nourished child of that age and sex. This anthropometric indicator can indicate wasting (ie, low weight-for-height, indicating acute weight loss), or much more commonly, stunting (ie, low height-for-age, indicating chronic restriction of a child's potential growth). Those two conditions can have different determinants and respond to different interventions.13 Therefore, consideration of wasting and stunting is more useful than consideration of underweight. This series primarily uses these two indicators, but also presents information on underweight because weight-for-age has been used in previous analyses.9, 10, 11 Reduction of fetal growth restriction and micronutrient deficiencies is also essential to achieving the MDGs and deserves high priority, even though there are no MDG indicators for these conditions. This Series also examines the consequences of low body-mass index and short stature in women.
This paper consists mainly of new analyses of the prevalence of nutritional conditions, risk factors, and consequent disease burden; if this was not possible or necessary, previously published results are presented. The burden of disease attributable to maternal and child undernutrition is presented for three world regions—Africa, Asia, and Latin America—that include primarily low-income and middle-income countries; only 1% of deaths in children younger than 5 years occur outside these regions. UN regions and subregions (webtable 1) were used.