If you stop drinking water will it help you to lose weight fast?

Not drinking water will dehydrate you and as a result will show you lighter on the scale temporarily. Dehydration can be very dangerous and even life threatening. It can cause such symptoms as depression, and lethargy and long term can cause serious health problems involving the kidneys. Avoid "lose weight fast" solutions as they tend to not stick, and opt for a lifestyle change that includes a healthy diet, regular exercise including cardio and resistance training, and a generally more active lifestyle.