Angie, I know what you are going through with your daughter.  My daughter is 18 and has SWCAH.  She has fought weight gain her whole life.  She goes up and down and I know that’s not good for you.  I try to cook healthy meals.  I also struggle with weight and due to an attack of pancreatitis last summer I have to really limit my fats.  My husband is diabetic, so he has to wtch carbs.  It is a real balancing act, but it is do-able.  We eat no fast foods, no fried foods, read labels on everything that comes into the house.  I use the internet for low-fat recipes and there are lots of good ones out there.  We exercise.  I like to walk and that is really good for weight control.  Right now my daughter is having serious hip problems and having surgery tomorrow, so she has not been able to exercise for months.  During that time, she has gained some weight back, so I know exercise really makes a difference.  I think it is harder for CAHers to maintain a healthy weight because of the steriods, but if the meds are in line, I think the lifestyle changes can be very beneficial.  One thing I would not do is to call any of it "going on a diet", rather "eating a healthy diet."  No one wants to feel deprived.  Good luck and let us know how it turns out.  I know this has been a difficult part of CAH for my daughter.