Not eating is sadly not a sustainable system. You can't keep doing it forever, and weight you lose from starving yourself is mostly water weight that will come back when you start eating again. I was anorexic for a few years and got kicked out of school and sent to treatment, and I learned that by not eating, the starvation was making my brain chemistry change in such a way that it fed into the cycle - by not eating, the starvation was making me more critical of my body, more critical of my mistakes, more depressed. The further it went, the harder it was to get out of it.

The healthier ways really are better. I wouldn't want to see anyone get sick like that.