Background/Objective. A discrepancy often emerges between nutritional goals and actual delivery. This study assesses the relationship between energy balance and length of stay (LOS) in surgical intensive care unit (SICU) patients. SICU patients are frequently catabolic and at risk of underfeeding. We set forth to identify if a nutritional algorithm will improve energy delivery and outcomes. Methods. A prospective observational study conducted in surgical critical care patients was performed. After implementation of a nutrition algorithm; demographic data, initiation of feeding, acquiring caloric goal, caloric deficit, LOS, and mortality were recorded. Cumulative energy balance was calculated as energy delivery minus daily target. Data are presented as mean ± standard deviation. Results. In all, 100 patients aged 66 ± 17 years (45% female and 55% male) admitted to the SICU were evaluated. All were nutritionally compromised, with 72% being NPO (nothing by mouth), 9% orally fed, and 9% enterally fed. SICU LOS was 4.9 ± 10.6 days; 60-day mortality was 3%; and time to goal feeding was 13 ± 10 hours. Mean daily energy delivery was 1459 ± 268 kcal/d. Cumulative energy balance was between −6401 ± 6404 kcal, with 12 patients having a >10 000 kcal deficit, 3 patients a >20 000 kcal deficit, and 1 patient a >30 000 kcal deficit. Conclusions. A nutritional algorithm will improve energy delivery and outcomes in critically ill patients. Accumulation of caloric deficit >5000 kcal is associated with increased SICU LOS and hospital LOS. Clinical implications. Nutritional algorithms and caloric deficit calculations are an underused critical care tool. The nutritional algorithm presented allows faster attainment of caloric goals, shorter LOS, and improvement in outcome.