Food THAT WILL FUCKING KILL YOU.

Alcohol
Partially Hydronated Vegetable Oil
Yellow 5
Red 40
Aspartame
Cyclamate
Saccharin
Homogenized Milk
High Fructose Corn Syrup

It would be more harmful for you to avoid fats and oils entirely than to overconsume (within reason mind you, eating a tub of lard is a bad idea no matter which way you look at it).

Same with sugars, meat, whatever.  Only problem is that in times immemorial, those were the harder foods to attain, so we're adjusted to seek them out more than vegetables.  We were in an almost constant lack of protein, fats oils, what have you.  That's why they taste so good, they're concentrated sources of energy. 

But energy is not in short supply anymore.