Our research focuses predominantly on the interactions between infection, immunity and malnutrition, particularly in the context of HIV infection. Undernutrition contributes to 45% of child deaths in developing countries, yet we do not fully understand the pathophysiology of malnutrition, or the best interventions for prevention and treatment. Stunting is the most prevalent form of undernutrition, affecting 165 million children under 5 years of age globally, and there are ambitious targets to reduce prevalence by 40% between 2010 and 2025. However, due to population growth, the absolute number of stunted children in sub-Saharan Africa is likely to increase and we lack understanding of the most tractable pathways to target for prevention. Severe acute malnutrition (wasting) affects an estimated 52 million children under 5 years of age and has particularly high mortality in the context of HIV infection. The pathophysiology of severe acute malnutrition in HIV-infected children is not well understood but urgent new interventions are needed to reduce the 30% mortality associated with this condition.