Dont worry I had one that did the same thing and I took him to the doctor several times. Now he is a thriving 15year old that eats me out of house and home he didnt like many fruits and vegies until much later in life. Babies at that age will pick one food and eat that each meal everyday, Mac and cheese was his meal of choice. As the doctor told me his body knows what it needs and as long as they are healthy just enjoy the time. It was great advice, he is a happy healthy young man and eats everything in sight now.