Peri-operative nutrition.

Patients are frequently malnourished or are at risk of malnutrition before surgery. Peri-operative nutritional support can improve their outcomes. This review focuses on new developments in peri-operative nutrition, including: patient preparation and pre-operative fasting; the role of nutritional supplementation; the optimal route and timing of nutrient delivery; and the nutritional management of specific groups including critically ill, obese and elderly patients.