Is 300 calories a day healthy?

It's obviously not healthy, come on! Most people have around 2000 calories a day. I've done the ana boot camp diet which lets you have about the same about of calories. The blacking out and lightheadedness is because you are undernourished. Try having a normal eating day of at least 1200 calories to keep you from getting sick.I don't promote these eating habits because they can leave you with a eating disorder.