I would advocate personally engaging in a ketogenic diet to assess for your unique personal experiential response. It is simple enough, not at all unhealthy if done correctly, and is worthwhile for many potential benefits if you are willing to engage such a disciplined nutritional undertaking.
For most, there will be an enhanced degree of sense of well-being with generally concommitant enhanced clarity and focus once the transition is made by the brain to adapt to a metabolic preferential state that utilizes ketones predominantly for energy requirements over glucose. This adaptation varies among individuals, but generally is within a period of 1-3 weeks.
There are many sites on the net to engage ketosis rapidly and with greater effectiveness.
CR also has some similar benefits. The body/brain has adapted to stay in a more optimized and heightened state when it sense any degree of restriction/starvation. Generally speaking, a well-fed (especiallu overfed) body is a lazy(lazier) body/brain (RE: sub-optimal)
Just do as necessary to maintain optimal nutrition, especially the essentials such as Omega-3s, multi-vit/mineral, etc. - amongst other benefical supplementation that should foster best results.
Best of Success