it would also be a demonstration that there is such a thing as "skill at making sense of the world."
There probably isn't such a thing with visible advantage for most topics that enough people already worked on.
A summary of the diet/nutrition literature which sorts the well-established points from the chaff would be extremely useful. Is there already a comprehensive online user-friendly treatment, written by extremely rational thinker(s) who have done thorough research? I would be surprised. The area is a minefield of cleverly disguised bad research.
Holden Karnofsky of GiveWell.org interviewed Jasen Murray of SIAI and published his notes (Edit: PDF, thanks lukeprog!), with updates from later conversations. Lots of stuff to take an interest in there - thanks to jsalvatier for drawing our attention to it. One new bit of information stands out in particular: