I would advice you to have fresh fruits.
If you feel very boring to eat fruits you can have yummy fruit salad.
You can have vegetable soup and also veggie salad.
This surgery was done to my brother when he was just 9. it was very painful i remember.
As you described about your work and your age i would advice you to take 7weeks rest to complete heal. And you can have light diet.
It totally depends on the type of body of a person. If suits and effected to burn the fat then it will really help you. Yes Cycling will burn your fat only when your empty belly. You can have luke warm water .