[RunbikeSki]

Although there is really no such thing as a "bad" food, there are foods that are bad for you when eaten in large quantities.
Carbohydrates are essential to life, but living on simple carbohydrates alone will (I want to say "kill" but that's a little too dramatic, so I'll go with) harm you.

I agree with Mike, when I focus on lowering my carbohydrate intake I almost always increase my intake of healthier foods, without increasing calories.