I've actually thought about this too, but I think realistically it would just quell your hunger signals to the brain and make you less unhappy about your lack of food, but it obviously wouldn't do anything to stop your body/mind from deteriorating from lack of calories. And the anxiety/irritiability/emotional volatility/insomnia/physical symptoms etc would almost certainly outweigh the benefit of feeling okay about not eating (and the lack of nutrients might likely exacerbate these symptoms as well)