Brain Fog

I can't ignore this issue because it's so common when you come from a diet of pizza and beer to a strict paleo-type diet. Brain fog happens when your blood sugar is low. Your brain prefers running on glucose. When you don't supply your brain with glucose from dietary sources, it will use the glucose that is stored in your liver and muscle cells. However, once those stores run out, your body starts to produce ketones from your fat cells. It takes quite a long time (at least for me it does) to get used to a brain running on ketones. You'll notice your ability to concentrate fall dramatically. This isn't really a bad thing. Your body just needs a couple of weeks to adjust to the sudden disappearance of potato chips and milk shakes. Once your insulin levels are not chronically high and come to a natural level, the brain fog disappears. If you really have to, just have a piece of chocolate or fruit. This should give you a little energy boost. In the long run, a paleo-type type will keep your blood sugar far more stable than a high carb diet because there are no insulin spikes.