If I'm working out in the evening (an hour of cardio at, say, 8pm-9pm), should I have dinner before or afterwards? What effects will it have on a) my workout if I eat beforehand and b) my recovery if I eat afterwards?

(If I were to eat before the workout, then I'd top up afterwards with a recovery drink of some sort – usually skimmed milk, yoghurt, blended banana, and Nesquick.)