I try to stay away from sugar, without denying myself completely of sweets. I also work out about 3 times a week on the ellipitical at work for 30 minutes. Drink lots of Water as well!
I think the rate you lose kind of coorelates with how much you need to lose. If you study the spreadsheet you'll notice most of us who were the heaviest before surgery, have taken it off quicker. I am only 5' 2'' and was 278lbs. before I began my preop diet. I lost 21 lbs. before surgery, which I felt was a lot of weight to lose in just 10 days. I'm sure most of it was probably water weight.
However, I do know for a fact that the amount of lean muscle an individual has, the faster their body will burn the fat off. This is why men tend to lose weight faster than women. Most of my weight is around my abdomen, but my legs have always been very muscular (like body builder legs, literally). Also, studies have shown that people who carry the majority of their weight on their abdomens have an easier time shedding the weight. Everyone loses weight differently, so I think my success has been due to my own geniune physical makeup more than anything. Still it seems we've each been successful in our weight loss no matter at what rate we're losing it.