I found this article today and thought it was interesting.

INTRODUCTION TO THE PALEOLITHIC DIET

Dr. Ben Balzer, family physician

It is interesting because this is a concept that I have thought about for several years and did not realize it officially existed.  Despite all the fad diets and different weight loss options that are available, rarely do they look at the basic biology of who we are.  We are mammals that were never meant to eat the diets we have today.
Of course, I do believe that even a "paleolithic diet" can be taken to extreme but it's basic principles are correct.  We would all likely be healthier if we ate a diet more similar to that of our ancestors.

I would also like to add another caveat.  Along with eating less potatoes, grains, and processed foods, I suggest we consider what WORK our ancestors would have had to do to eat.  Foods such as fruits and vegetables would have been readily available and fairly simple to obtain.  Therefore, we could eat all we wanted.  Meats on the other hand would have taken  more work.  Fish would have been easiest, followed by poultry, and then red meat.  A large animal would have only been killed occasionally and red meat eaten rarely.  Humans also would have expended huge energy resources to catch their prey.  Something we unfortunately no longer do.

Just food for thought.  As you eat your next meal, think about what energy might have been used in obtaining that meal.  Did you exercise today?