Standard predictive equations may under- or overestimate caloric requirements in disease states such as obesity or in patients with a low body mass index (BMI). Although this principle is common knowledge among nutrition specialists, it is often not prioritized with other clinicians outside the intensive care unit (ICU). Indirect calorimetry (IC) is often used in the ICU to estimate caloric requirements. This article outlines a very complicated case of a cachectic man with an enterocutaneous fistula who had lost more than 50% of body weight over 2 years. In rehabilitating this patient, we found that the most common formulas of basal needs greatly underestimated the calories required to prepare him for restorative surgery. Key learning points are that in malnourished ambulatory patients, predictive equations may not adequately estimate caloric needs and IC may be required.
Keywords: calorimetry; enteral nutrition; home nutrition support; nutrition assessment; nutritional support; parenteral nutrition.