The image of armed confl ict often evokes visions of malnutrition arising from deliberate starvation policies, neglect, or the helplessness of parties to the confl ict to cope with the humanitarian consequences of war. For decades now, nutritional action has been confi ned to the immediate response to malnutrition. Food aid and nutritional rehabilitation have been the humanitarian reaction to major crises, based on a simple equation: crisis = food shortage = malnutrition. This simplistic view did not shed light on either the causes or the mechanisms of crisis. This Manual departs from such a restrictive view. The author approaches nutrition from two different angles, from which he derives practical recommendations for humanitarian action. The fi rst provides an in-depth understanding of nutrition, based on a coherent range of information on the notions of nutritional need and food intake that goes beyond the usual checklists on these topics. The social dimensions of food are likewise discussed thoroughly, avoiding the pitfall of strictly quantitative analysis. This fi rst part provides the scientifi c basis of the Manual. The second angle contemplates nutrition at its broadest. It demonstrates the interrelations between nutrition and other relevant sectors, notably the economy. It places nutrition within the legal framework set by international humanitarian law (IHL); as such, it reminds humanitarian operators that the operational response to nutritional disorder is not simply technical, but also pertains to the protection of the victims’ rights to have access to food in times of confl ict. From these two angles, the author analyses the impact of armed confl ict at all levels: human, political, economic, ecological, social, cultural, and physiological. Vulnerability is examined at all these levels. This section provides the keystone of the Manual because it provides the link with the need for integrated approaches in recommended responses. This overall approach guides the reader through the chapters devoted to the “classic” nutritional action types, namely general food distributions and nutritional rehabilitation. The author discusses them in terms of planning: is such action required and, if so, how should it be carried out? Questioning the need for general food distributions encourages humanitarian operators to examine their relevance in terms of context and alternative forms of response, thus leading naturally to a multidisciplinary analysis. The discussion on the practical implementation of general food distributions and nutritional rehabilitation programmes rests upon the scientifi c basis described in previous chapters, lending additional credibility to the recommended procedures. The author shares his personal fi eld experience with readers, and has connected scientifi c theory and practice – he thereby provides nutritional operations with a professional basis, which should become the standard in humanitarian action. All humanitarian operators involved in nutrition should read, but above all study, this Manual.