The surgery would not affect your weight in any way. As long as their is no medical problem that needs attention, such as Cushing s syndrome, hypothyroidism, or polycystic ovaries...the following might be a good read for you: Weight, is a reflection of your our dietary habits and exercise routine. As long as we continue to consume calories more than our body needs, and more than what we burn up during a day, the excess energy is converted into fat, and stored. The overall process of putting on weight is slow, so one seldom notices how that weight got there. The same goes for losing weight, one tends to lose weight as slowly as it was put on, provided that either the caloric intake is restricted or, exercise is undertaken to burn of what is eaten plus a bit more. So, in order to lose weight, the best approach would be, cutting down on your caloric intake, and avoiding fatty foods. Take up exercise, maybe a brisk walk would be good enough, for five days a week. The combined effect of reduced caloric intake, and more calories burned up would yield a net weight loss. The loss in weight would be steady, say 0.5 kilos a week...so persistence is the objective. All the best with your surgery, and goodluck to your weight loss plans!