I am not too skinny; that is just others peoples opinion. I am of normal weight for my height and age, and I feel great. It seems worse than it is because I went from 12 stone to 10 after I stopped weight training. Also, I am Indian, so everyone thinks that being over weight is healthy and a sign of wealth. They just don't learn from all the heart attacks and diabetes.
I think I eat very well. I believe in getting the best, freshest food I can, having a well balanced diet (which includes fats) and in the traceability of food. I do have a gluten and cow's milk intolerance, so I guess I don't eat that much, if any, refined carbs; however, I do eat other flours and other sources of dairy. If you're eating well, feeling good and are 'skinny', I think you should be okay. If you're worried then you should probably go and see a doctor or nutritionist.
Umm... Doesn't being too skinny mean you're not eating well? (I'm asking because I'm in the same situation).