My son is almost 5 months old, has his two bottom teeth and showing a lot of the other signs he is ready to eat. However, he doesn't like cereal at all. I have even mixed it with breast milk and he will not have it. He acts like he wants food when we are eating but won't have the cereal. Any suggestion? I have read that you have to start them on cereal and add other things step by step to watch for allergies. His weight is OK now but the gaining is slowing and he is very long so he looks thinner.