McDonalds tends to be very electric-heavy in the kitchen since they have mostly custom-designed appliances that use electric heating. Electrical subcontractors have told me that a typical standalone McDonalds restaurant has a 1200A 208V 3-phase service or larger. That's over 400,000 watts of service capacity.I should think McDonalds would use quite a bit as everything seems to be electric - heavy duty cords hanging all over the place! Just all the "beeping" going on there probably uses quite a bit in itself!
But many regular restaurants use gas ranges, so might not be as much electric use.
Here it says a McDonalds uses 16,000–28,000 KWh per month...
http://www.powersines.com/var/56/522535-CS ComEC McDonald's.pdf