I dont have my op for another 20 days, but in all honesty Im not sure that I've ever been 'hungry' and think many of us would be the same. True hunger, the haven't had anything for a long time need food hunger.
Much of it is head hunger and habitual. Make new habits, sip the shake as suggested above. Grab some low cal Jelly if need be but remember it's probably not real hunger.
Eating is such a part of our lives whether it be social, habitual, just love the smell, bored, happy, sad... the works - almost everything presents itself to 'food' so we need to find another way of dealing with all that stuff.
I'm hoping I will have more energy to do something other than eat as my hobby when the time comes