According to an Urdu language booklet I have, there are 2 different patterns for "want" (it should be the same in Hindi):
want STH = sth + चाहिए
want TO DO STH = verb-ना + चाहता/ती/ते हूँ/हो/है/हैं
He wants food = उसे खाना चाहिए
He wants to eat = वह खाना चाहता है
So I would translate "he does not want to eat" by "वह खाना नहीं चाहता है".
Please anyone correct me if I'm wrong.