Wow. This post originated in 2008!
Junk food, to me, is anything that is "super processed" - if it has crazy ingredients you can't pronounce, is super-carby or super-sugary, etc. THAT'S junk food to me. Potato chips - junk food. Any kind of candy!!! - & while home baked goodies (cookies, pies, cakes, etc.) are not the BEST of the food world, they CAN BE MADE HEALTHY (well, healthIER) by using less sugar, etc. so I don't always count those either. But candies, pop-tarts, sugary cereals... yeah, junk food. And some foods that try to fool you into believing their "health foods" like granola bars - that's junk food too (to me). Chef-Boy-R-Dee type things in a can - yup, junk food.
Ice cream... on the fence. Something simple like Breyers Vanilla - it's made with 3 simple ingredients. So, not junk food. But your basic cheap-o generic brand vanilla? Got lots more ingredients... junk food.
I don't consider cheeseburgers, fries, etc junk food. Maybe not the HEALTHIEST thing one could choose, but still, not junk food. Unless that's all you eat. I know some people that drive thru McDonald's for breakfast & lunch every day. EVERY DAY. Blech.