My 3 year old is having an eating disorder ,what shall i do??/?

she hates food and now she's hating the food that she once liked (kit kat and snickers)..and if i force her to eat she will vomit.......what will i do??her weight is only 11 kilos and she looks like a skeleton and has delayed speech...

3 year olds don't have eating disorders. My eldest daughter did the same thing when she was about 2 years old and again at 5 years of age. When I took her to the doctor, he told me to leave her alone, watch for dehydration, give her plenty of water or other liquids, and that when she got hungry she'll come to me for food. Within 2 weeks she started eating again. To be on the safe side, take her to your physician anyway, there could possibly be something wrong with her and she cannot formulate the correct words to be able to tell you.

Get her to a physician ASAP!!!!!!! Most likely she has someting physically wrong with her that is causing her to not want to eat. It sounds like it is MUCH more than a mental issue!
get her to a doctor fast. but for the meantime, let her choose between a selection of foods which has the same caloric value. that way she wont have to be forced to eat on what she doesnt like.
Get her into an early childhood intervention program. There is something going on and the multidisciplinary team will get to the bottom of this.
Get help fast! This most likley isn't an eating disorder. Get her to a good, nearby doctor ASAP!!

But in the meantime, try to get her to eat anything[without forcing her]. Take her to any place, [restraunts, cafes, gas stations,] and have her pick out anything she would eat. But most important, keep her hydrated! Good luck.
You must take her to a doctor, and make sure a pediatrician. At three years old she can't always articulate when she may not feeling well. She will need a thourough examination. It is not normal for her to vomit like that, even if she doesn't like the food.