Talk to your doctor. One of the side effects of Seratonin Reuptake Inhibitors (SRI) is reduction of appetite. If you find yourself eating when you're depressed, that's a big clue, and you can kill 2 birds with one stone cheaper than these diet plans.
Do you have any experience with these? My doctor just put me on Lexapro (which is an SRI) for the purpose of helping me to lose weight. I do eat when I'm depressed & I hope this helps me. I've started walking too.