DS1 has never been a particularly good eater but there was a reasonable range of things that he would eat - although he doesn't eat anything in great quantity.
Over the last few months, he has stopped eating about 50% of stuff that he used to love (such as fish fingers and cheese) declaring that he doesn't like them.
What can I do? The only meat products he will eat are sausages and billy bear meat - won't touch any other kind of meat. He hates tomatos which counts out bolognaise and lasagne (although, to be fair, he has always hated tomatos!)
Out of 15 choices on the school dinners, he will eat 5 of them (and 2 of those involve sausages) 
He also won't touch something if it "looks funny" etc.
What can I do? DS2, who has always eaten very well and tried pretty much anything, is starting to copy DS1 and refusing to eat stuff too.