In this excerpt from his new book Neurofitness , Dr. Jandial — a college dropout turned neurosurgeon — explains why intermittent fasting is so good for the brain. Perhaps there is a reason why most of the world’s major religions call for periodic fasting. Intermittent hunger clears the mind, awakens the senses, and improves brain functioning. Plus it lowers your blood sugar, reduces your insulin levels, and helps you lose weight by reducing total calories. What’s not to love? Well, the hunger. But it only lasts for a short time! Consider our prehistoric ancestors, the hunters and gatherers who survived through feast and famine, abundance and scarcity. The real “ Paleo diet ” didn’t consist of just large hunks of meat. Many were the days and weeks they failed to catch an auroch or boar and went to sleep hungry. But with the hunger pangs come benefits. Going without food for even a day increases your brain’s natural growth factors, which support the survival and grow...