Timeliness of nutrition intervention is essential to preventing idiopathic hospital malnutrition. The aim of this observational study was to determine why physicians do not implement dietitian consult recommendations. The behavior and beliefs of physicians around nutrition consults were evaluated with a retrospective chart review and a computer-based survey of 582 participants. Nutrition support accounted for 78% of the physician consults. Physicians implemented only 39% of 77 dietitian recommendations for tube feeding and parenteral nutrition formulas. Several of the physician beliefs were identified as barriers to the implementation of nutrition consult recommendations. Thus, protocols and clinical privileges can expedite implementation of registered dietitian nutrition recommendations.