How long before the effects of malnutrition kick in?

Question

I'm on a diet that consists of only a small low calorie dinner(most of the time) with mostly water. I guess I am lacking a lot nutrients that I need. How long before I start to threaten my own body. Its been almost a month and 18 pounds lost.

Answer 1

Actually, the very first day that you deprived yourself of less than 1000 calories, your metabolism slowed. Each day since, it has slowed even more and your body feeds off muscles, which provide more energy than fat. So, you are technically "fatter" than before you began.
I suggest you begin taking a multivitamen and eating a healthy, well balanced diet rich in fruits, vegetables, whole grains, protien, and calcium. You can still loose weight and eat healthy amounts of food.
Before too long, you will start losing hair, getting paler, constantly irritable, and your immune system will be so low that you will catch every flu and cold coming & going.

Answer 2

Diet is a matter of habit, nothing happens by malnutrition in one or two days; after that energy level starts reducing.

Answer 3

those 18lbs were probably from water weight and muscle.

You hit malnutrition right when you started that diet.

Answer 4

Your muscles should be cannibalizing themselves by now.