We had the same problem with my great grandmother. She lived with us for two years with alzheimers. She would only eat brownies, cookies, honey buns... basically just junk food. The doctor said just to let her eat what she could and wanted. He said to also see if she would drink protein drinks like ensure to make sure she got some vitamins. Luckily, my mom would pour a can in a glass and she thought they were chocolate milk and would drink a couple a day. There's really not much you can do when they just plain out refuse to eat.

My mother is still not a sweets eater, or else that would work. She has been given the strawberry boost, its like nesure because the vanilla and the chocolate are just to sweet for her.....
so after the 2 years did your grandma go into a nursing home?