My nephew has high functioning autism and he was/is horrible with eating. He will be 5 years old next month. He started talking late and had all types of food aversions, and no matter what you did he would NOT put the food in his mouth and my sister tried everything. She ended having to send a lunch to daycare that was food he would for sure eat because otherwise he would get really moody from hunger.

It ended up being a waiting game, now that he is more verbal my sister has more success at getting him to eat a more varying diet. It was very stressful for their family, his refusal to eat resulted in constipation and other problems. He still has aversions, he physically gags on macaroni but is fine eating any other kind of pasta.

He has been going for speech therapy and occupational therapy since he was 2, it seems to have done alot of good.

I don't think there is much you can do, just keep offering and hopefully it will work out in the long run.