I would suggest mixing fruits with it. My daughter also quit eating hers about 2 3 months ago I have been getting her the diced green beans and carrots. I dont know if an 8 month old is ready for that stage yet though they say if she /he can pick foods up between her thumb and finger she is ready. Guess it all depends on what she is use to eating.
Hope I helped
I know that my neice went through the same thing around the time she was two. Before my sister was so careful and I mean this baby ate nothing but healthy. Now she will only eat chicken nuggets, and pizza. I know the doctor said that is was a phase and to indulge her as long as she was eating, he said it would pass and that it wasnt a big deal. We just make sure she takes her vitamins, which she loves.