I think having meaning and purpose in your day to day life is required to escape from these sorts of thought patterns. Ray has this fascinating quote on appetite here and relates it to a function of our own will, or the will of each of our cells working towards a common goal. If you have purose in your life, food and diet become simply something that serves that purpose - and so you learn quickly which foods are most effective for you. It's hard to do anything without a stable source of calories and nutrients though. Cyproheptadine could help in such a transitory period, Sun & Steel by Yukio Mishima, too.