No. Walk away from any DJ who requires a meal. They should be excited for your wedding – not the free food. There is no reason they can not eat something right before the wedding starts.
Now I will say that it is greatly appreciated when a vendor meal is presented – but it is never a requirement. I also will not eat in front of your guests. No one wants to see the DJ (or any vendor for that matter) woofing down food. Just not a good look. If I do eat, I will woof it down out of sight but close enough that I can still hear the music.