I am a healthy 26 year old woman. This may sound hard to believe but from age 18 months to about age 4 I lived on peanut butter toast for breakfast and peanut butter sandwiches for lunch and dinner. I also drank milk with it but that was it and that is no exaggeration. My mother thought I was going to be malnourished or suffer vitamin deficiencies from this inadequate diet. But I turned out okay. I'm not saying your grandchild's diet is good, but don't fret. My parents and grandparents tried making me sit at the table until I ate a meal. It didn't work. I'd sit for an hour or two without taking a bite. All I can remember is having a phobia of real foods especially green vegetables. Finally, my mom bribed me by saying she would buy me a bicycle if I'd eat a piece of meat. It worked! I'm not saying this is the answer. Now I love all foods even spinach! Thankfully, my daughter is a very good eater, but when I want her to eat a green vegetable or something I tell her that Barney eats these and that's how he became so strong and smart! She instantly eats it then, b/c Barney is her idol. The other thing I would suggest is DO NOT give junk food. Only offer real food even if all she eats is a peanut butter sandwich. My parents would never even keep junk food in the house, so we had no choice. But I lived on peanut butter for about 3 or 4 years. It is popular
story in my family. Also you may want to give Flinstones vitamins. Good luck!