Like any other restrictive "diet", don't start on it unless you're willing to stay on it for the rest of your life. If you stop, you body will over-react to whatever it is you had been "restricting" and you'll end up bigger than when you started.
The only way to lose weight properly is to be sensible. Eat more fruits & veggies. Avoid processed foods. And exercise like you fucking mean it! At least 3 days a week, go to the gym & work out a few hours. Weight train. Gain muscle and your metobalism will increase and you'll burn fat just sleeping.