Body mass index (BMI) has been commonly used to identify critically ill patients at risk of malnutrition, but BMI does not distinguish between tissues such as muscle mass, fat, or edema during hospitalization[6] Other markers, such as serum albumin, prealbumin, among others, do not reflect the nutritional reality of critically ill patients, since there is an increase in acute phase protein synthesis at the expense of albumin synthesis in cases of severe acute diseases[7]. Here, ALB is linked to malnutrition.