Can you lose 30 pounds on a 1000 - 1200 calorie per day diet?

If you eat 100 calories a day, you'll lose weight, but your metabolism will slow down significantly and in the long run, you'll gain weight. You'll also do damage to your organs. Yes, you will lose weight. You will also get ill. Keep it up for more than a few days and you will start to lose your hair and your teeth as your body starts to digest itself and you slowly starve to death.