"They want food."
Translation:उन्हें खाना चाहिए।
Typically "unhe chahie" is a little more like "need", and "want" would be "voh chahta hai", I think?
Not quite. चाहिए is 'want' if used with a noun, and is inerchangeable with चाहता है. So मैं खाना चाहता हूँ would be okay here too. चाहिए can also be used to mean 'should' when used with a verb: मुझे जाना चाहिए (I should go). If you want to say 'need' you use ज़रूरत: मूझे खाना की ज़रूरत है (I need food, literally it means 'To me food's need is').
Well fair enough that 'zarurat' is stronger than 'chahie', but in any case as it is it's only accepting 'chahie' and not 'chahta hai'