I fast for 16 hours during some days of a week. I often break my fast after my morning exercise (Gym/Tennis/Running).
Only eating between noon and 8 PM helped me eliminate brain fog.
Fasting activates autophagy which is the body's process of cleansing at cell level. This is the major reason for health improvements related to it.
Dr. Jason Fung - 'Therapeutic Fasting - Solving the Two-Compartment Problem' - Amazing talk.
Benefits of Fasting
Great discussions around health benefits of fasting