Interesting insights here Oliver. I recently cutback on my coffee consumption by about 80% and have noticed a slight increase in my focus as a result of not being so jittery. That being said, I have become a huge fan of Bulletproof Coffee mixed with some grass fed butter and MCT Oil. It is the ultimate in terms of peak energy and Keto-based fat burning.

I highly recommend any of the books by Bulletproof founder Dave Asprey on this topic.