Malnutrition is associated with an increased risk of morbidity and mortality. Individuals with chronic, severe illnesses are particularly vulnerable. Timely recognition of nutritional deficiencies and ensuring adequate food intake are the responsibilities of caregivers. This book presents current, evidence-based knowledge on the detection and treatment of malnutrition. At-risk patient groups, such as children, the elderly, and patients with oncological diseases or dementia, are given special consideration. The consequences of malnutrition are highlighted, with a particular focus on chronic wounds and frailty. Special attention is paid to nursing measures that promote oral nutrition and the implementation of expert standards within interdisciplinary teams. Ethical questions regarding the handling of food are also addressed.