The State of Food Insecurity in the World reports on global and national efforts to reach the goal set by the 1996 World Food Summit: to reduce by half the number of undernourished people in the world by the year 2015. The crafters of the Summit Plan of Action felt that great progress could be made towards this objective if countries could focus on the following three questions: Who are the food-insecure? Where are they located? Why are they food-insecure? These three questions form the subject of the first section of this year's report. Entitled Undernourishment around the world, it provides FAO's most recent estimates of the prevalence of undernourishment and the absolute number of undernourished in 125 countries for the period 1997-99. The section "Assessing nutritional status and vulnerability" describes practical methods that have either been used in the past or are currently being developed in different countries to identify segments of the population exhibiting physical signs of malnutrition and, subsequently, to analyse the livelihoods of the people concerned so as to address the income risks underlying their vulnerability. These patterns of hunger and vulnerability are greatly complicated by continuing severe national shocks from natural and human-induced disasters and from the ballooning menace of the HIV/AIDS epidemic. The section of "The State of Food Insecurity in the World 2001, Action against undernutrition and poverty," provides some illustrative answers to a fourth question: What can be done? Among the actions proposed are the more accurate targeting of food aid, and measures to improve access to clean water - both essential factors for assuring people the basic energy and health to participate in creating a better future for themselves.