Nutrition and health in women, children, and adolescent girls

Health effects of malnutrition

The consequences of malnutrition could hardly be more serious: around 45% of child deaths in 2011 were due to malnutrition (including fetal growth restriction, suboptimal breast feeding, stunting, wasting, and deficiencies of vitamin A and zinc). In 2013 the growth of around 161 million children aged under 5 was stunted by chronic undernutrition, leading to hampered cognitive and physical development, poor health, and an increased risk of degenerative diseases.3 In the same year 51 million children were wasted (having low weight for height) because of acute undernutrition; severe wasting increases the risk of morbidity, particularly from infectious diseases such as diarrhoea, pneumonia, and measles, and is responsible for as many as two million deaths a year.4

Meanwhile, deficiencies of vitamin A and zinc cause many deaths (157 000 and 116 000 child deaths, respectively, in 2011),5 and iodine and iron deficiencies, along with stunting, contribute to children not achieving their full potential. Iron and calcium deficiencies increase the risks associated with pregnancy, particularly maternal mortality.5

At the same time overweight and obesity in children and adults have been increasing rapidly in all regions of the world, and half a billion adults were affected by obesity in 2010. Dietary risk factors, together with inadequate physical activity, were responsible for 10% of the global burden of disease and disability in 2010.6

Socioeconomic impact of malnutrition

Malnutrition contributes to an estimated 200 million children failing to attain their full development potential. Stunting is estimated to reduce a country’s gross domestic product by as much as 3%,7 and eliminating anaemia could increase adult productivity by 5-17%.8

Every $1 (£0.64; €0.91) invested in tackling undernutrition is estimated to yield around $18 in return—the median benefit:cost ratio from a study modelling the effect of preventing one third of stunting in children up to age 3 in 17 high burden countries. 9 More specifically, a recent study of the benefit:cost ratio of a package of nutrition interventions aimed at averting stunting in 15 countries found that benefits outweighed costs by as much as 42:1, depending on the existing economic and nutritional situation.10

Better understanding of the challenges and solutions

The root causes of malnutrition and the factors leading to it are complex and multidimensional. Poverty, underdevelopment, and low socioeconomic status are major contributors, along with other social determinants. Current food systems struggle to provide adequate, safe, and diversified foods. The reasons include constraints on access to land, water, and other resources—often aggravated by environmental damage—along with unsustainable production and consumption patterns, food losses and waste, and unequal distribution and access. Malnutrition is often aggravated by poor feeding and care practices for infants and young children, as well as poor sanitation and hygiene. A lack of access to education, quality health systems, and safe drinking water can also have a negative effect, along with infectious disease and the ingestion of harmful contaminants.

In recent years progress has been made in developing knowledge and understanding of the magnitude and scope of nutritional challenges, the increasing contribution of non-communicable diseases, and the complex web of factors that can influence nutrition.

A greater understanding has developed regarding the importance of nutrition at different stages of the life course and the effect of poor nutrition across generations (fig 1⇓). An intergenerational cycle of malnutrition exists whereby a woman who has anaemia, for example, is likely to have a baby with a reduced birth weight. Low birthweight babies are more likely to be wasted or stunted and to have a higher risk of morbidity and mortality and of developing non-communicable diseases later in life. Conversely, if the mother is obese when she starts her pregnancy she is also at increased risk of complications during pregnancy or delivery, which could result in premature delivery—and, therefore, a low birth weight for her baby. Alternatively, if she carries the baby to full term, her baby is more likely to have a higher birth weight and a higher risk of child and adolescent obesity.

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Fig Nutrition through the life course—proposed causal links13

Reproduced from WHO childhood overweight policy brief, based on figure from Darnton-Hill I, Nishida C, James WPT. A life course approach to diet, nutrition and the prevention of chronic diseases. Public Health Nutr 2004;7:101-21.

The past two decades have also seen a major shift in understanding of the policy responses required to improve nutrition and promote healthy diets. It is now clear that an enabling environment plays a key role and that policies that change aspects of the food environment are required (such as what foods are available, what levels of fat, sugar, or salt they contain, or how much they cost), as well as nutrition education and information.

Similarly, there is now much greater awareness that effective responses need to come from beyond the health sector and that this must involve other sectors, such as those related to water and sanitation, education, trade, and social protection. Crucially, a radical transformation is needed so that food systems can ensure that everyone has access to a sustainable, balanced, and healthy diet.

Progress towards global nutrition targets

Significant progress has been made in reducing hunger and undernutrition in the past two decades: the percentage of people in developing regions experiencing hunger fell from 24% in 1990-92 to 14% in 2011-13.14 The 2014 Global Nutrition Report showed, however, that the world is not on track to meet any of the six World Health Assembly nutrition targets (table 1⇓).

Actions to improve adolescent girls’ nutrition

Adolescent girls should be at the heart of a life course approach—a young adolescent girl is still a child, but often she will soon become a mother. Adolescent pregnancy is associated with higher risk of maternal mortality and morbidity, stillbirths, neonatal deaths, preterm births, and low birth weight. In addition to actions to prevent adolescent pregnancy and encourage pregnancy spacing, efforts are required to ensure that pregnant and lactating teenage mothers are adequately nourished.

Actions to improve child nutrition

The first 1000 days of life (from pregnancy to the child’s second birthday) present an important window of opportunity to improve child nutrition. The key pillar of any strategy to improve this—in addition to good maternal nutrition and health—is optimal feeding and care for infants and young children. Exclusive breast feeding (defined as the practice of giving an infant only breast milk for the first six months of life, with no other food or water), in particular, has the single largest potential effect on child mortality of any preventive intervention. Timely and adequate complementary feeding, with particular attention to vitamin and mineral content and the nutrient density of foods, is urgently needed.

Actions to improve women’s nutrition

The health and nutrition statuses of women and children are intimately linked. Improving the health of women and children, therefore, begins with ensuring the health and nutritional status of women throughout all stages of life, and it continues with women being providers for their children and families. Thus, a key priority is female empowerment and women’s full and equal access to, and control over, social protection and resources such as income, land, water, and technology. Direct multisectoral actions to tackle critical women’s nutritional challenges, such as iron deficiency anaemia, need to be rolled out on a larger scale to achieve universal coverage.

Improving nutrition across the life course

These targeted recommendations must be supported by a raft of nutrition interventions throughout the life course (see the ICN2 Framework for Action for the full range of recommended actions). Policies are needed, for example, to transform food systems and strengthen health systems. Universal access to functioning and resilient health systems and the scaled-up delivery of interventions can improve nutrition. Governments and international organisations also have a role in developing clear guidelines on healthy diets.