These proteins are now known to be negative acute phase proteins, which means their levels decrease in response to inflammation and physiologic stress. Because they are not specific for nutritional status, failure of these levels to increase with nutrition repletion does not mean that nutrition therapy is inadequate. Although their usefulness in diagnosing malnutrition is limited, these proteins may help identify patients at high risk for morbidity, mortality, and malnutrition . BMI and some or all of the components of a subjective global assessment (Box 1.1) are commonly used to assess nutrition.