He is too young for you to worry about food groups and giving him meals. His milk is his primary source of nutrition til a year old. When you first start solids, it's about getting used to tastes and textures. At this age, 3 meals of food a day is too much, usually just two servings of solids. If your baby's doctor hasn't discussed introducing solids, be aware that you should introduce only one new food to your baby at a time, waiting a few days before introducing the next fruit, vegetable or other foood. He doesn't need to eat breakfast, lunch and dinner - he needs to continue getting the same amount of milk, and twice a day after nursing (or bottle), a small amount of solids.