Lots of hydration and protein, possibly vitamin supplements as needed. Minimize salt and fat intake. Definitely discuss with your surgeon her/his recommendations. I talk to my patients about pineapple intake and Arnica utilization to help reduce swelling and bruising beyond the usual diet recommendations.
I recommend a liquid diet the first day and then add solid foods as desired. Your appetite may be reduced after surgery but it will soon return. Be sure to stay hydrated. Check with your plastic surgeon for more recommendations. Best wishes.