What do I mean by optimal? Think about it from the perspective of a race car - it's designed to run on high octane fuel. If you put regular 87 in it you're putting in a "tolerable" fuel source. The car will still run, but you're going to gunk up your engine and get poor performance out of the car. When you put in the "optimal" fuel, high octane 93 or racing fuel, your car doesn't just run, but it runs optimally - you'll notice that it has great performance, it responds better, etc. Your body responds the same way to what you put in it. Anything with fat, carbs, and protein is considered food. I believe Paleo foods are truly your optimal food source, based on the way your body breaks them down at a nutritional level and then how your body uses those nutrients to fuel your body and brain.
One of the common questions or concerns about switching to a Paleo diet is that you will be missing out on essential vitamins and minerals: Where are you going to get your fiber? and What about calcium? are two of the most common questions I get. When you compare Paleo based meals to the "healthy" Standard American diet meals you will see that the Paleo meal is always higher in vitamins and minerals every time. You can get fiber naturally from eating whole fruits and vegetables. Calcium is a bit more complicated to understand, but you can get calcium from leafy green vegetables (like broccoli) and when you change to eating Paleo foods you better manage the acid/base balance that your body struggles to maintain - primarily through the leaching of calcium from your bones. Now do you understand how a nation that consumes so much dairy could also have a problem with osteoporosis.
The next time you make a food choice, think about what you are putting in your body - personally I'm going for the real, whole foods verses the newest flavor of cheerios which is claiming to have 20% of my daily recommended intake of fiber. How much fiber do you think is in the veggies in my omelette or in the avacado...definately more than 20% RDA.