I wonder if the hard wiring is part of evolution dealing with famines and lack of food in the past? It would be advantageous to be more food focussed if food is scarce and you'd be more likely to survive and pass on your genes to the next generation in times of scarcity.
The problem comes now when there's loads of food about (if you can afford to buy it) and it's not always the best sort of things to eat (burgers, pizzas, chocolate etc), but you still feel tempted to eat it anyway.
I know I struggle with my will power and will have to be on some sort of diet, probably calorie restricted, forever, to keep on the straight and narrow. And I have a sedantry job, so am unlikely to burn off weight with my vigourous typing and phone answering.
But I keep trying, even if I fall short sometimes, and short of having a gastric band fitted, there's not much else I can do about it.