Couple of times I've walked into Hungry Jacks (AU version of BK) and walked straight out again when I smelled the burning fat filling the store. Yecccchhh.
Make your own burgers instead... they can look as good as this and taste a whole lot better, and if you cook them right they'll have far less saturated fat.
<img src="http://www.burgerking.com.sv/burgerking/images/doublewhopper.gif">