Stunting of linear growth, a highly prevalent problem in children of low- and middle-income countries, is the result of exposures of the fetus and/or infant to nutritional deficiencies and infectious diseases. Maternal undernutrition results in fetal growth restriction and infectious diseases in pregnancy can result in preterm delivery. Both of these conditions are important contributors to stunting in early childhood, albeit their relative contribution varies by world region. After birth growth faltering may begin at 3-5 months of life and becomes more prominent from 6-18 months. During this time the young child is exposed to many infectious diseases, such as diarrhea, that have an adverse effect on growth. There is also increasing evidence that frequent exposure to enteric pathogens and toxins, such as mycotoxins, result in damage to the small intestine.
The resulting condition, referred to as environmental enteric dysfunction, even without clinical symptoms, can cause growth failure. Furthermore, the complementary foods that the child receives in addition to breastmilk are often inadequate in nutrients and energy, negatively affecting growth. The harmful exposures during the critical period for growth and development of pregnancy and the first two years of life, have led to programmatic focus on this “1000 days” in the life cycle. Infection control and dietary interventions, including nutrition education and for undernourished women provision of food supplements during pregnancy, result in improvements in birth outcomes that position the newborn for healthier growth. Interventions in the first two years of life include promotion of exclusive breastfeeding for the first six months of life and continued breastfeeding for at least the first two years and nutritional counseling to assure adequate complementary feeding and if necessary in food insecure areas the provision of supplemental food to be given to the child.
Control of exposure to enteric pathogens and toxins is also important to prevent adverse effects on child growth and the development of stunting. Evidence shows that each of the interventions has a beneficial effect on the growth of the young child, yet that effect is modest in relation to the degree of stunting observed in these underprivileged populations. Nevertheless, rapid reductions in the prevalence of stunting in some low-income countries in recent years shows that substantial improvements are possible as a result of social and economic change along with specific infection control and dietary interventions.