At birth, children born in low- and middle-income countries are generally below the average length-for-age on the WHO’s growth charts. Chronic malnutrition causes a further decline in their rate of linear growth within the 1,000-day window, with little or no recovery thereafter. Inadequate diets are associated with stunting. Nevertheless, nutrition programs have only had a modest impact on the growth of these children. In this presentation, Prendergast explains how recurrent infections may be implicated in the aetiology of stunting. Data shows that diarrhoea has a significant impact on height. Children living in environments of poor sanitation and hygiene are continuously exposed to pathogenic microbes. This causes a change in intestinal structure and function. Improvements in water, sanitation and hygiene may well address this environmental enteric dysfunction, and promote linear growth.