Attending to the nutrition needs of people affected by crisis forms a cornerstone of humanitarian response. Malnutrition can be caused or worsened by disaster that destroys livelihoods, infrastructure and food resources -- creating situations of prolonged poor access to food. Equally, high levels of malnutrition itself may define the primary crisis itself. Malnutrition often disproportionately affects vulnerable groups such as destitute populations lacking the resources to cope with shortages or children, who have lower energy reserves than adults. Malnutrition has a direct impact on health and growth, such as resistance to illness or diseases caused by the lack of specific nutrients. In programming terms, nutrition is often closely linked to Food Security.