When reducing calories to lose weight, do not cut calories by more than 15% (150-300 calories) of your daily calorie maintenance needs.

If you cut more calories from your daily diet, there are very less chances that you'll be able to stick to the diet for long. Also, if you cut calories drastically, it will do you more harm than good. Your body can go in the starvation mode, as a result of which the body holds fat very efficiently.