Diuretics are a quick way to help you lose weight fast. The weight you lose from diuretics have to do with water retention. If you are the type of person that retains water you can lose pounds in just one day with a diuretic. Natural diuretics may help relieve water retention by making you urinate more. But there is little if any scientific evidence of their diuretic effects, so you may not find them effective. And if you're aiming for long-term weight loss, natural diuretics probably won't help.