Paleo is not for me. OMG, did he just say that? He can't say that. I just did, deal with it.
Crossfit HQ prescribes zone/paleo for eating. Zone was created by Dr. Barry Sears and involves weighing and measuring food to ensure that the proper quantity of macronutrients is consumed at the right time throughout the day. Paleo ignores the precision and is about getting Crossfitters to consume quality foods and to get rid of garbage.
I believe that any number of eating methods are valid. If you are vegan, awesome. This will turn the inflammation dial way down, will allow digestion to speed up, and will get rid of a ton of the waste product that lies in the folds of the intestines. Getting adequate calories and protein will be paramount.
The US government's food prescription suggests that you should divide your plate into four parts. 30% grains, 30% veggies, 20% fruits, 20% protein is what they think makes sense. In addition, you should have a glass of milk at every meal.
Paleo is meat and veggies, nuts and seeds, some fruit, little starch, no sugar. Conspicuously missing are grains, which used to be the basis for the FDA food pyramid in their last attempt before going for the 'choose my plate' prescription. This means no pasta, rice, or bread. Also excluded are legumes (including peanuts) and dairy (which is supposed to be at every meal according to the US government). Let's forget the promotion of the grain and dairy industries through farm subsidies given by the government.
In rejecting grains, legumes and dairy, paleo gets rid of a number of ingredients to your diet that cause massive inflammation in your internal organs. When I get rid of grains, I lean out fast due to the loss of water retention. Paleo makes me feel clean and is what I choose to follow when I'm travelling or am not Crossfitting.
When I am Crossfitting hard, I choose to ignore paleo. I find that without rice, I feel tired during met-cons. My joints don't feel as fluid in opening and closing efficiently. My heavy lifting suffers and my mind is not as sharp. My self-talk when going into max lifts or a set of cleans is decidedly less positive. Performance suffers if I don't eat grains.
Body composition definitely gets worse when I eat grains, but since performance is better when I consume rice, this trumps everything. In Crossfit, we chase performance, not having a beach body. I believe with all my heart in Crossfit theory. That is, that VO2 max, lactate threshold, body composition, strength and flexibility are simply correlates to fitness and shouldn't be considered the one true thing. Increasing work capacity across broad time and modal domains is superior to specialization for overall health and general fitness.
I have a long way to go before picking up Crossfit as a competitive sport. When I can do 30 muscle ups for time, 25 handstand push ups and deadlift 400 lbs, maybe then I can start with micro-cycles and specialization, but until then I'm going to do whatever I can to chase performance as a recreational Crossfitter. I compete with myself, and with the other athletes in my box, but I will not risk injury of more than a week or two. I will be sensible and listen to what my body is telling me. You only get one body, don't do irreparable damage and you will thank yourself.