This is a common sign of depression - and as Leed said that depression affects people in different ways sometimes it's loss of apetite. I would suggest to you that you try and find the cause of this depression and if you very honestly can't think of one then you should perhaps see a therapist or if you can't get out of your depression either you should seek help! I really hope you find what is causing all of this and I hope you feel better soon Take care!