Losing weight is very hard to accomplish.  When you are determined to lose weight, you do just about anything to lose it quickly.  But losing weight too quickly just to get that great body can pose some serious problems.

Losing weight too quickly can mess up your metabolism because you will lose more muscle with the fat.   Messing your metabolism could lead to plateau and relapse.  The weight loss will also be temporary because you are likely to gain weight again.

In losing weight, the most important thing to get rid off is the fat.  Your weight loss should come from fat loss or mostly fat with a minimal loss in lean mass.
The safest and permanent way to lose weight is to lose about two pounds per week.  Never go on crash diets or overexert your body with too much workout.  Patience is the key to losing weight.  Take the pounds off slowly and steadily with an intelligent diet and exercise program to lose the weight in a healthy and permanent way.