 [ Symptoms ] crazy weight gain on birth control  i am under eating i have an eating disorder but getting help and i exercise vigorously for 6 days a week but i am retaining crazy amounts of founding and gaining weight like crazy what is going on i am a teen runner out on the pill to gain a period back [ Disease ] here is some information that i hope will be helpful to you and your daughter as she waits to see her doctor ovarian cysts ovarian cysts & tumors ovarian cancer the webmd answers staff