PReoperative Very Low Energy Diets for Obese PAtients Undergoing Non-bariatric Surgery

"The preoperative VLED protocol will utilize Optifast 900, a commercially available weight loss product sold by Nestlé Health Sciences. Optifast 900 is designed as a high-protein, low-carbohydrate, and low-fat meal replacement with complete micronutrient composition. Instructions for use are as follows:~1. Consume 4 Optifast 900 packets each day~2. Take 1 sachet of Optifast 900 once in the morning (AM), once at noon, once in the early evening (PM #1), and once later in the evening (PM #2) for three-weeks.~3. Mix 1 sachet with at least 300 mL (1 1⁄4 cups) of cold water. Shake well or blend in a blender."