Last reviewed 03/2022

Malnutrition is a condition of abnormal nutritional intake for normal homeostasis.

This may be either due to insufficient or excessive intake of many dietary elements, or an imbalance of intake of such elements. A range of clinical syndromes result.

Practically, malnutrition is often considered in terms of protein and energy. Energy balance is determined to be positive or negative on the basis of input - enteral or parenteral nutrition - and output - heat and work. Negative balance results in catabolism of body energy stores, primarily fat and protein, with subsequent loss of weight.