Malnutrition is one of the components of comprehensive geriatric assessment (CGA), but the mini nutritional assessment (MNA), which is the proposed screening tool in geriatrics, was challenged in its capacity to predict adverse outcomes in severely ill older patients. Therefore, we showed that body composition was predictive of mortality and could be useful in the assessment of malnutrition replacing or in addition to the MNA. CGA and further recommendations can decrease the rate of adverse outcomes after an emergency department (ED)-visit like ED readmission, nursing home admission, functional decline, and death. As CGA is time-consuming and ED is particularly challenging about this topic, screening tools were developed, targeting high-risk patients who are the most likely to benefit from CGA. We showed that one of these screening tools avoided performing CGA in patients who were negatively screened.