Can I tell you about my DD? She is 15, and is a normal happy bright girl. She has no major health issues or special needs at all. I have a second DD who eats most things and loves her food!
DD1 never liked eating. I wanted to breast feed but couldn't, so she was FF. She loved her bottles of milk, although had a problem with projectile vomiting for a while. When I started weaning her (at 16 weeks as recommended at the time) she just wasn't interested and spat everything out. I tried home made purées and jars, but the only thing she seemed to enjoy was powdered baby food that came free in my bounty pack. Even then she would only eat a few spoonfuls a day. She eventually would eat jars of baby food (nothing home-made!) but never ate lumpy baby food. At 2 years old she would only eat the jars of food without lumps.
We have always offered her our food to try, and by the time she started school she would eat 'proper' food, but very small amounts, and only a few familiar foods. She would never have eaten school dinners for example.
I mentioned it to doctors and health visitors, but because she was otherwise healthy, although skinny, they weren't worried.
She just is fussy. It seems to be more texture rather than taste, for example, she will eat a poached egg, but will cut all the white off (it's slimy) and just eat the yolk. Someone mentioned peas and sweetcorn on this thread - she will eat them separately, if they are mixed, she will sort them and then eat them.
She eats toast, marmite, one breakfast cereal only, pasta with butter, fish in batter, sausages (specific brand), chicken nuggets, chips (only sometimes), lasagne, pasta with sauce (no lumps!), potatoes (boiled or mashed), tinned pasta and sausages (Heinz only, this is her favourite, she would quite happily eat this and nothing else!) roast dinner with some vegetables, plain pizza, scrambled eggs, paté, and I think that's about it. She also loves very salty food, so I have to limit the amount of salt she adds to her food. We try and eat quite healthily, so don't really want to eat her type of food!
She eats very few vegetables, no fruit except apples (I have never met anyone else who doesn't like any fruit), no salad. If we have a Chinese meal she will eat plain rice, prawn crackers, prawn toast, and chicken balls with no sauce. If we have an Indian meal, she has chicken and chips, and doesn't really enjoy it much. She did try some dry chicken tikka a few weeks ago, and quite liked it! Hooray!
She only drinks water, and some squashes, but hates fizzy drinks. That's one good thing about her being fussy!
We have just learned to get on with it, it is just the way she is. She is getting a little better as she gets older, but it is very slow progress. Incidentally, she was very shy when she was little, and hated mother and toddler groups etc. She is still a little shy and quiet, but enjoys school, has plenty of friends, and is generally happy.
Sorry, this is quite long, but I hope it's helpful to those of you with younger children.