At 7 months solids are going to be such a new thing for him, I would not push it at all, let him take the lead in terms of how much he wants to eat and when to add more food. All babies are so different, at 7 months my ds was barely taking in one meal of cereal! At this age, formula or bfing is the most important aspect of their meals and the main source of nutrition, solids are for tasting and learning about textures. What is his reaction to the solids? Have you tried experimenting with the texture/consistency, selection, etc., and he just isn't too interested in the food overall? Could he be teething? I find my ds has been eating less this past week for this reason. Not sure about the nws, if his formula intake has not changed, has anything else changed- his naps, or anything?