When I was 14, my parents sent me to France to live with a family over the Summer, in the hope that I would learn some French and come back mature, well-rounded and independent (and I think they wanted a break from my teenage mega-strops). I did come back speaking French, so it half worked. Not only was it a linguistic journey, it was also a culinary experience that has stayed with me to this day.
The family I was inflicted upon were called the Chevaliers and they took me with them to their chalet by the sea in St. Jean de Monts on the West coast of France. We always ate outside which was a huge novelty for me, but even more of a culture shock was what we ate. Day 1: lunch began with a plate of a dozen oysters with a wedge of lemon. Madame Chevalier told me in fast, unforgiving French to squeeze my lemon onto an oyster to check if it... and this is where I thought I couldn't possibly have understood her correctly. But when I saw the glistening oyster twitch as she dripped some lemon juice over it, I realised that I should have trusted my language skills because, clearly 'reculer' did indeed mean 'recoil'.
I was horrified but had been brought up to be polite so I somehow ate the oysters even though the alien taste and texture (and all that recoiling) made me gag. Day 2: We sat down for lunch and I figured that whatever it was, it couldn't be as bad as the oysters and that as I'd got through that, I could get through pretty much anything. Out came lunch and it was... a dozen oysters. Wow.
Day 3: lunch was again, a dozen oysters. By now, I was able to let them slip down quickly at it wasn't so much of an ordeal. Day 4: a dozen oysters. You get the picture. Two weeks in I had a realisation - I was starting to like them! By the time I left France, I LOVED oysters and still do to this day.
So why am I telling you this? I'm not suggesting you restrict your child to a diet of oysters and lemon juice but I think that this story demonstrates the importance of repeated exposure to disliked foods. Palates really do change and develop with experience. A study I often quote found that while it can take up to 15 exposures to a new food before a child starts to like it, on average the mother's studied gave up after 2.5 exposures.
So never give up! Serve your child new and disliked foods again and again...and again. One day they might surprise you.