There is little argument over the health benefits of fruits and vegetables. They are chock-full of vitamins, minerals, fiber and antioxidants. The only caveat for paleo dieters is that some vegetables are starchy (e.g., potatoes) and some fruits are higher in sugar (e.g., bananas). So, if you are trying to lose weight or watch your blood sugar levels, eat these in moderation. In fact, potatoes are banned from some strict versions of the diet.
Do not eat grains. This includes (but is not limited to) wheat, rye, barley, oats, corn, rice, millet, bulgur, sorghum, sprouted grains, and all gluten-free pseudo-cereals like quinoa, amaranth, and buckwheat. This also includes all the ways we add wheat, corn, and rice into our foods in the form of bran, germ, starch, and so on. Again, read your labels.
In 2007, the first annual CrossFit Games were contested in Aromas, California, on a small ranch owned by the family of Games director Dave Castro. For the initial Games in 2007 and 2008, participation was open to anyone who made it to Aromas. The Games would also award an Affiliate Cup to the group from one CrossFit gym that had the best combined individual standings. In 2009, competitors had to qualify after over a hundred athletes had shown up in 2008. The athletes earned an invitation through either placing high enough in the previous year or through placing in the top worldwide in a set of qualifying events called Regionals hosted at a few CrossFit gyms. The CrossFit Games also added a separate set of team-based events for the Affiliate Cup, marking the first use of a designated Team Division, with teams of four (two men and two women).
Of course Wikipedia has a page on the Paleolithic Diet. It is quite thorough. It also isn't clear about the lean/fatty meat debate between the followers of Loren Cordain and a slew of others, and pushes lean meat. It is weak on the variations of the diet. Then it restricts fermented beverages. Even butterflies eat fermented fruit. Why wouldn't our paleo ancestors also?
The rationale for the Paleolithic diet derives from proponents' claims relating to evolutionary medicine.:594 Advocates of the diet state that humans were genetically adapted to eating specifically those foods that were readily available to them in their local environments. These foods therefore shaped the nutritional needs of Paleolithic humans. They argue that the physiology and metabolism of modern humans have changed little since the Paleolithic era.:594–95 Natural selection is a long process, and the cultural and lifestyle changes introduced by western culture have occurred quickly. The argument is that modern humans have therefore not been able to adapt to the new circumstances. The agricultural revolution brought the addition of grains and dairy to the diet.
The following links tend towards news reports of scientific studies that point out some positive aspect of the paleo diet. If you are looking for current news reports, I suggest signing up for Google Alerts for the Type: News. I have three set up, for: "caveman diet," "paleo diet," and "paleolithic diet." You can also set them up for blogs and/or websites.
This 2003 CrossFit Journal article captures an early conception of a universal, multi-event test of fitness that laid the foundation for CrossFit competition, including what would become the CrossFit Open and the CrossFit Games. The design requirements for such a test "included but were not limited to the following: quantifiable results; consistency with the CrossFit fitness concept; raising our commitment to improving absolute strength, relative strength, and gymnastic foundations; balancing intrinsic abilities of smaller and larger athletes; emphasizing exercises critical to and foundational to advanced training; mixing training demands within each test and, of course, over the total competition; a design that would identify an athlete’s weaknesses and possibly stand as a workout plan for improving overall fitness; and, finally, we wanted to design a competition that would be 'hard as hell.'"