because it's what you want to do.
So it feels like that? That is good. And anyway - no one EVER starts on 200kcals a day. You don't just wake up one day and say 'today I'm going to eat under 200kcals'. You cut out little bits and pieces, here and there. You shrink meals, and shrink them, then you skip one, shrink the others, skip one, maybe two.. By that point, your stomach has shrunk. You can't possibly just cut out to so few calories without building up to it.
Yes, some of this programme is good, well researched, and generally fantastic, but don't try it yourself. Errk.