Malnutrition is one of the world’s most serious but least-addressed development challenges. Its human and economic costs are enormous, falling hardest on the poor, women, and children. In 2017, 151 million children were stunted (low height-for-age), which indicates not only a failure to achieve one’s own genetic potential for height but is also a predictor of many other developmental constraints, including cognitive deficits and future economic opportunities, including impeding a country’s ability to accumulate human capital.
Since the 1990s, the worldwide prevalence of stunting declined from 40 percent in 1990 to 22 percent in 2017. However, stark regional differences persist, with South Asia and Sub-Saharan Africa remaining above the global average both in terms of prevalence and numbers of stunted children. Approximately 35 percent of all children under five were stunted in South Asia in 2017, decreasing from 61 percent in 1990. Even though the prevalence of child stunting in Sub-Saharan Africa fell from 49 percent in 1990 to 34 percent in 2017, the total number of stunted children in Africa increased by 13.9 million during the same period as a result of high fertility rates and lower rates of decline in stunting.
Stunting early in a child’s life can cause irreversible damage to cognitive development and has educational, income, and productivity consequences that reach far into adulthood. The economic costs of undernutrition, in terms of lost national productivity and economic growth, are significant—ranging from 2 to 3% of GDP in some countries and up to 11% of GDP in Africa and Asia each year.
Fortunately, these losses are largely preventable if adequate investments in proven interventions are made, particularly those that focus on ensuring optimal nutrition in the critical 1000-day window between the start of a woman’s pregnancy and her child’s second birthday.
Globally, undernutrition is more common in poor households, but is also prevalent among wealthier households. Income is one—but not the only—determinant of stunting: food insecurity, diets lacking in diversity, high rates of infectious diseases and inappropriate infant feeding and care practices, and poor sanitation and hygiene practices also contribute to persistent stunting. Food and financial crises, as well as conflict and natural disasters, have worsened undernutrition in many regions.
At the same time, a global nutrition transition is underway, leading to rapid changes in food systems, environments, and living conditions in many low- and middle-income countries (LMICs). These changes have stimulated a rapid increase in the burden of overweight/obesity, previously considered an ailment of wealthy countries. In fact, over the past 30 years, rates of overweight have risen faster in LMICs than in high income countries, and every region has seen some increase in the prevalence in overweight children under five years. Overweight is now pervasive even in countries where children experience undernutrition.
Countries are now starting to experience the double burden of overweight among both adults and children and stunting among children. Today, more of the world’s overweight individuals reside in low- and middle-income countries than in high income countries, and there is no evidence that the rise in obesity in LMICs will decline. As countries experience economic growth and achieve middle and upper-middle income status, their poor will experience a greater share of the burden of overweight and obesity, increasing their vulnerability to health and economic shocks. There is an urgent need to ensure that the world’s poor have access to the knowledge, resources, and services needed to achieve optimum nutrition.
lastupdated: Apr 01, 2019