Two Sources

First Source:
I have been doing a lot of reading and research about the Paleolithic diet, or people may know it as the caveman diet. This was the food that our ancestors 2.5 million years ago were eating. They had been doing this until about 10,000 years ago when we were introduced to agriculture and grain-based diets. The paleolithic diet is made up of mainly fish, lean meats, eggs, vegetables, fruits, and nuts. The diet has shown improved health outcomes and a lot more energy in daily activities. There has been a lot of reports saying that this is the one diet that people do not choose because they never see an outcome. Well, i'm sure that is true because we have no idea how to eat just these foods when we have processed foods, breads, and fast food all around us. In the past 10,000 years, our bodies had to adapt to all the new foods that were never in our diet before. That is such a short period of time for our bodies to evolve, and that is why we have such a problem now with weight and health issues.
I found this source using google, and just typing in "paleo diet." I chose Wiki as my first choice, because it has a lot of background information about the diet, and also has opposing views, which I believe is always necessary to look at. 
Title: Paleolithic Diet
Paleolithic Diet

Second Source:
I have read in this article that the paleolithic diet is what suits us best. It has the proper balance of nutrients to promote health and reduce the incidence of chronic diseases. This diet is very healthy, and does not involve us eating any grains or dairy, because our bodies have still not been able to adjust to those foods. Most people who do the paleo diet are gluten free and eat lean meats, because it is hard to mimic the exact diet since we do not have wild game available daily. This diet is not chosen by many people, because there is no artificial sweeteners. You can sometimes have raw honey or coconut palm sugar but only in moderation. While doing the paleo diet it is also recommended to get good exercise since our ancestors had to hunt and travel for the foods all the time. There is also cheats that come with the diet. You don't have to be extremely strict with foods, some people add peanut butter every once in a while. I think this is a credible source, because the information is coming from WebMD from experts, and I also found this by typing "paleo diet" into google.
Title: The Caveman (Paleo) Diet
Last Edited in 2008
Author: Kathleen Zelman, MPH, RD
Paleolithic Diet