Why is losing weight too quickly bad for your health?

Faster,PussyCat-Kill: Because the body has little time to adjust metabolically and the mind has not had the time to adjust to the point that your habits will change. It's a needless stress. Doesn't mean you shouldn't or couldn't do it but it probably means you're in it for a quick fix and will most likely relapse. A diet should be for life, not just for the Cote d'Azur this Fall. Find a good book on proper diet habits.