How Does Fasting Affect the Brain?
And that’s what we’re finding in lab animals — the brain and body actually perform better during fasting. In the case of the brain, cognitive function, learning, memory, and alertness are all increased by fasting. And in the body, we recently found that mice maintained on an alternate-day fasting diet during a month of treadmill training have better endurance than mice fed every day. So intermittent fasting enhanced the mice’s physical performance.
Source: How Does Fasting Affect the Brain?