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.