There is nothing more discouraging than stepping on the scale after a week of diligent dieting and grueling workouts and not seeing any drop in the number. The plateau is a common problem among dieters and can typically be waited out, but there are measures you can take to keep your metabolism fired up even as you reduce your caloric intake.
The best way to break a plateau is to keep your salt intake below 2,000 milligrams a day and drink lots of water. Make sure you're not eating any processed carbs, period. That's right — no chips, sugar, white flour, and so on. And hit the gym hard! The boost in exercise will make your body swell and hold fluids for a few days, but after a week you should see the benefits on the scale.
You can also try playing around with your caloric intake a bit, varying it from day to day throughout the week while keeping the same weekly total. The body can't slow its metabolism to adjust to a reduced caloric intake if the intake isn't fixed from one day to the next. For instance, to bust my plateau, I might have 1,200 calories on Monday, Wednesday, and Friday and then eat 1,500 calories on Tuesday, 1,600 on Thursday, 1,400 on Saturday, and 1,700 on Sunday. Get it?
The plateau effect can sometimes simply be a matter of flagging resolve. If mixing up your caloric intake just isn't working, make sure you're not slipping up on your diet or slacking off in your workouts. I'm serious; it happens.
As with any program, there will be highs and lows, but stay with it. Your body is trying to adjust to the weight loss. Don't get scared or discouraged. Just be patient and know that you are worth it!