To change or not to change

So I guess it is all about change. Change your lifestyle. Change your diet. Change this and that.
My son has had constant ear infections and colds and now asthma and eczema since starting day care at 16 months of age. He has been on all kinds of antibiotics, steroids, asthma treatments and had ear tubes put in.

He eats mostly fruit and some veggies, very little processed food and milk but loves cheese and chicken. So I am reading a lot about how diet can play a huge role in his medical conditions. So do I change his diet drastically? Eliminate all dairy and cheese? Eliminate meat? Maybe give him some organic chicken a few times a week at most. I am willing to do what ever it takes to get him healthy and keep him that way. It is hard to know what to do. I ask the doctor and he says his diet is fine but if you look at what the experts are saying about linking kids diets to these chronic ailments it looks like I still need to tweak what he eats.

Change or not change? I am going to continue my research for now. We already started eliminating cheese. Poor thing. So far he has not asked about it but I know he will. More fruit and veggies are never a bad thing but how much can I get him to eat will be the real question. He will always eat fruit. It will be the veggies we will struggle with.