While CrossFit looks to the Zone Diet for food quantity, quality of food tends to fall under the Palaeolithic Diet: http://www.earth360.com/diet_paleodiet_balzer.html

It can’t be pure coincidence that the foods that humans have developed since the first agricultural revolution (bread, pasta, rice, potatoes, corn…) are the same high-glycemic foods that we must now attempt to limit in our diets in order to prevent hormonal imbalance. The first humans weren’t clearing the rainforest to grow Big Macs, they were hunters and gatherers. The Zone Diet reflects this emphasis on simple, whole foods; the Paleo Diet takes it a step further: eliminate everything that a hunter/gatherer would not have access to… anything processed. That leaves you with: lean protein (wild game, fish), vegetables, fruits, berries, nuts, and seeds… sound familiar?! The Paleo Diet is easy to do in conjunction with the Zone Diet: forget about grains, limit or eliminate dairy, and love those vegetables! It’s the easiest way to exponentially improve your health.

Think you’ll be hungry or bored of eating the same food? Try my favourite 4 block Paleo-Zone meal: a giant spinach salad made with 2 cups spinach, 3 oz chicken, 1 hardboiled egg, 6 chopped mushrooms, ½ yellow pepper, ¼ cucumber, ¼ cup carrots, ⅓ cup onion, as much celery and alfafa sprouts as you want, ½ apple/orange, ⅓ cup raspberries, ¼ cup blueberries… (literally any combination of veggies/fruits you find in your fridge!), and a couple olives or a sprinkle of sunflower seeds, with a dressing made from olive oil (3 tsp) and lime juice and garlic (both freebies!) to taste. Yummy!!! You can choose how strict you want to follow the many versions of the Paleo Diet… and you certainly don’t need to measure everything exactly, these are just to give you an idea of the portion sizes provided by the Zone Diet. For example, I often replace 1oz of chicken with 1.5oz of feta cheese in my salad and throw on some balsamic vinegar (also free!), and I love peanut butter, though legumes are dismissed by many Paleo followers. What you eat is up to you, but try to understand what you’re choosing to eat, and why.