What are empty calories? how bad or good are they?

Dietary fluff: The term "empty" calories is often used to describe the sugar in processed food, fruit juices or colas. They provide the sweet taste but provide little else to the consumer. No calorie substitutes can be used that provide similar taste but are not converted by most to fat.The "good calorie" label is applied to lean meats, high quality fats & carbs that support a healthy lifestyle.