I've done that too and he did learn the lesson. In my case, he didn't exactly go hungry but he was relegated to the dollar menu at McDonalds and no drink instead of going to a place he really enjoys. He tried to resolve the situation by calling his mom to ask for more money, but even though she said yes, I didn't let him get away with it. He shouldn't have had to ask for more to money to begin with, she had already given him money to hang out and he spent it on buying more of the same crap he already has too much of instead.

I think it's the right thing to do. My yf learned his lesson and I'm sure yours will too.