Dont give up homie. Maybe your grandma needs to get outside to get some fresh air. I know shes in her older sge, but sometimes people just need to get out & see something new. Or maybe she needs to be around stuff that reminds her of when she was younger, find out what she use to be intrested in & try to get her back into it, maybe she needs a hobby or some friendly company. Try to make her some of her fav foods & see if she eats that. If she keeps skipping out on eating, then maybe, & I really hate to say this homie but we gotta list all the possibiltys, maybe she needs to see a doctor to see if something else is wrong. I hope & pray that thier is nothing wrong, but its better to get it checked out sooner then later. Just keep your head up man & stay positive! WHOOP WHOOP!