When you fast long enough to activate your body’s metabolic switch (typically 12 or more hours), your mind and body stars running on super-charged energy molecules called ketones.
One reason “flipping your metabolic switch” is so beneficial for the brain is that ketones generate approximately 25% more energy in the body than glucose (sugar). So the shift that occurs in the course of fuel being used can give your brain an immediate boost.
Perhaps you have experienced moments of great mental clarity while fasting? This was one of my first experiences, and a big reason I became interested in what was happening in my brain while I was fasting.
Over time, I learned that when our bodies use ketones for energy, (after this metabolic switch is flipped), changes happen within our cells that have health-promoting effects in our minds and bodies.
One of these processes is called autophagy, which is the way cells clean themselves, so they can function better. And the cells in your brain are no different than the cells in your body.
You have likely noticed that when you wake up from a good night’s sleep your mind feels “fresher” and works better than when you went to bed. This is due, in large part, to the enhanced cleaning of the brain cells (neurons) that take place when we sleep and fast. You see, at night we all fast for several consecutive hours and think nothing of it.
So, if you can start the fasting process (aka not eating) a few hours before going to bed and then wait to eat for a few hours after waking up, you are well on your way to incorporating IF into your lifestyle and having cleaner brain cells.