Why am I so obsessed with food?

I love food and eating. I love a lot of variety. I love everything about food. I order sandwich platters just to eat all to myself. I am a greedy pig in all honesty but I can't help it, food is all I ever think about and I am constantly hungry all the time. I really want to lose weight but diets are hell for me because I end up feeling dizzy all the time and really hungry so I end up eating all the time again. Why is this?