But, I realized I've never really given a definition for "processed foods." Well, Emily Davidson over at Healthy Eating, Naturally does a bang up job of defining what processed foods are and why you should avoid them: http://healthyeatingnaturally.wordpress.com/2009/08/13/processed-food-vs-junk-food/#comment-315
"Processed food is food that has been heavily manufactured in order to be shelf-stable. Processed food rarely resembles anything from nature. Processed food fills the inner aisles of the grocery store; things like cereal, crackers, breads, bottled beverages, granola bars, and other snack foods. There is no
question that these foods are not part of a healthy diet. When a food undergoes so much manufacturing, it becomes nutritionally devoid. An enormous amount of
preservatives and other artificial ingredients are added to these foods to keep them “fresh.” In addition, a great deal of sugar and salt is often added to make these “foods” taste better. The healthiest foods are the ones closest to their
natural state. Our bodies are not designed to consume these man-made concoctions that America has come to accept as food. When we eat shrink-wrapped, boxed, bagged creations, we will not reach optimal health and weight. Calories are
irrelevant here; the food you eat is a lot more complex than calories. [For more on this, read my post, Confessions of an Ex-Calorie Counter.]"