How are they similar? Kenneth Anderson at The Volokh Conspiracy writes:
I have shaved my head completely, as I have discovered from long experience that even if it doesn’t help me discover my spiritual side, it weirdly helps me concentrate. I highly recommend it. I have much coffee, good stuff from Antigua Guatemala. Yerba mate from Paraguay. I have my extralight olive oil re the Seth Roberts diet – to which, although I realize I’m just bragging here – I sincerely credit the loss of 25 pounds [emphasis added] and a wholly unmedicated cholesterol score last week of 128 total and 66 good (!).
All three help you concentrate. (SLD helps you not be distracted by hunger.)