With my first cup of coffee of the morning, i'm drinking to the memory of Douglas Adams, the author of the Hitchhiker's Guide and Dirk Gently series of books. Though sciency-fictional, he presents an awful lot of practical truths for real life. My favorite is probably the concept of the SEP Field -- Somebody Else's Problem makes it easy for other people to ignore something that's really glaring....
Forty-Two, on the other hand, is the answer to Life, the Universe, and Everything. (The problem here is, the question ITSELF was never adequately defined.) Lots of ingenious questions whose answers equal 42 have been proposed. I just thought of a new one, while reading overnight tweets with my coffee.
FORTY-TWO is the minimum number of crucial lifestyle choices, leading to great health and tremendous fitness.
It's not gut-bugs, it's not early-to-bed-and-early-to-rise, it's not always burning fat for fuel, it's not always avoiding "high-reward" food. It's all those things ... plus a lot more.
We realize now that Ancel Keys was a self-important asshole with esteem issues, but all those people out there who are currently trying to carve a career by choosing ONE central concept as their signature FIX are treading dangerously near to his path. Becoming well-known on poorly-executed science will set you up for all kinds of reputation-wrecking down the road -- just look at Colin Campbell. ;-) Think how embarrassed some famous folks must be, when they have to back down from a pet cause because they found out too late that it was just plain WRONG.
We human beings like simple answers. We like short and snappy expressions of complex concepts, probably because having a firm understanding of ALL the laws of physics is much harder than parroting "conservation of energy/matter! SQWAAAAAK!"
But life is far from simple, and biology and biochemistry are far more detailed than we even know at this point. When I think of all the studies that haven't been done yet.... When we acknowledge that, though we put a man on the moon 45 years ago, we only are BEGINNING to understand the intricacies of leptin and glucagon, we have to admit that innerspace still holds an awful lot of mysteries.