No, he's an adult. You can be 100% sure he'll be managing fine at other "adult" things like pubbing, clubbing, having sex, maybe smoking, drug taking, etc. We do too much "infantilising" of our children generally and it does them no good in the long run.
A couple of generations ago, he'd have joined the working world a lot sooner than 18, working in dirty factories, coal mines, shipyards, etc. No, we don't want to go back there, but at that age, they're perfectly capable of being fully functional adults unless they have a genuine disability! In the wars, they were conscripted to go and fight at that age!
You need to set firm boundaries and he needs to learn, pretty damn quickly, how to budget and to understand money!
As others have said, if he genuinely has no money for food, then provide him with a couple of loafs of bread and a few tins of beans, a bag of pasta, etc. Just enough to stop him starving, but at the same time making him responsible for his actions. It's the only way they learn! They can't pretend their adults one minute and then keep coming crying to mummy because they've spent all their money on crap the next minute!