So, my diet isn't great...as I struggle to think of foods I would actually like to eat that are low Carb/GI or low calorie. I try my best in the week, but at the weekends I tend to eat white bread, tinned tomato soup and a bit of cake. I always gain a couple of pounds on the Monday. This week, I've only lost 1 of the pounds thus far. I have pcos, I'm on metformin, marvelon (combined pill) and sertraline. Could these be contributing to not losing water weight easily? Or to gaining water weight easily?