I recommend trying these two experiments:
1. For one week buy no food where you have to throw away packaging after. I didn't think I would be able to do it, but it profoundly changed how I eat and view food. Here is my experience: http://joshuaspodek.com/avoiding-food-packaging.
2. For one week, eat no food where fiber has been removed. Again, it seems challenging, but once you do it, you see food differently.
For most of human history, there was no food packaging nor did our ancestors take fiber out of nearly anything. The experiments should be simple. Actually, they are, once you lose the modern view of food being a product.