Lots of people have had weight gain problems with Celexa (citalopram) and Cipralex/Lexapro (escitalopram). Indeed most psychotropic drugs can potentially cause weight gain.
Advice for avoiding weight gain.
Firstly let’s cover the basics: try to eat well, make sure you eat whole foods, complex carbohydrates and keep refined sugars and processed fats to a minimum. Also, take plenty of exercise. Whether you are taking an SSRI for depression, panic attacks or anxiety, you are almost guaranteed to feel better to some extent just by exercising. It also of course keeps weight off.
Now the clever part: One hour or so before meals it a high carbohydrate snack. This could be some fruit, some oatcakes, even high cocoa content chocolate. Don’t eat too much, say a couple of hundred calories, and try to eat something that isn’t too refined, so your body burns it slowly.
You should then find that this carbohydrate snack has boosted the Serotonin levels in your brain and that this will limit your food cravings. (click here to understand why carbohydrates boost Serotonin levels.) Your appetite will return to more reasonable levels and you should keep/gain control of your weight. Worth a try anyway!