Along with the other posters ... I think it's a little early to worry about it. If you don't think he's getting enough nutrition then supplement, but really he's probably getting everything he needs through formula, and just keep trying ... maybe go back to the stage 2's for a bit. The only thing that triggered in me is sensory issues because I have 2 adopted kids with sensory integration problems and sometimes that shows up in eating .... they only like mushy food, or only like crunchy food. One of mine crunches up carrots and then spits them out because he just wants the crunchy sensation, not to really eat it. I wouldn't worry about this though ... just keep in mind if in 6 months you're still having problems.