When I hadn't lost for a while recently, I went back to keeping a Food Log (as I did in the six months prior to surgery for the nutritionist).
I was surprised to find that my calorie count was between 600 and 850 a day--so I didn't make any changes downward and sure enough the weight eventually began to drop again.
Here's my motto: my surgeon is my leader and I follow his instructions implicitly! You've put your trust in him up until now--so just continue and follow his recommendations...