Malnutrition and undernutrition

The term malnutrition is used to describe a deficiency, excess or imbalance of a wide range of nutrients, resulting in measurable adverse effects on body composition, function and clinical outcome. As such it can refer to individuals who are either over- or under-nourished, although it is usually used synonymously with undernutrition, as is the case in this article. Although it is well known that malnutrition is common in the developing world, the fact that it occurs quite frequently in UK health settings as a consequence of either psychosocial circumstances or the effects of illness or injury is not widely appreciated. Furthermore, since malnutrition has direct effects on clinical outcomes and is associated with massive healthcare expenditure, better recognition and treatment would result in improved patient outcomes, reduced costs and decreased medico-legal risks. It is therefore the responsibility of all doctors to recognize the fundamental importance of proper nutritional care. The focus of this article is primarily concerned with malnutrition and its consequences in the UK.