THE BLOG
12/19/2013 11:51 am ET Updated Feb 18, 2014

Feeding Homo Sapiens: Are We Truly as Clueless as We Seem?

If you happen to have tropical fish -- and I'm not saying you do, I'm just saying somebody does -- you feed them. If you have tropical fish and you don't feed them, it isn't long before they are, well, feeding the fish, if you know what I mean. Creatures eat or they die.

Since you (or the other guy) do feed your tropical fish, it seems to imply, ipso facto, that you know what to feed them. Hold that thought.

Meanwhile, back at the ranch, the ranchers know what to feed their horses. And then there are those remarkable zookeepers, who seem to know what to feed just about anybody. Their charges, after all, range from koala bears to gibbons to giant pandas to lions, tigers, bears, owls, pythons, hyenas and spiny anteaters (well, that last one is something of a give-away at feeding time, admittedly). All of these critters get fed or they suffer the fate of those tropical fish you starved to death two paragraphs ago.

I suppose there may be some obscure scientific literature on the intractable controversies of degustative zoology, but I have never found it. To the best of my knowledge, there are no such fierce debates about how to feed koala bears. There seems instead to be a prevailing acceptance that whatever the quirks and idiosyncrasies of individual koala bears, to say nothing of spiny anteaters, they are in fact all members of the same species, adapted to the same basic diet, and should dine accordingly. And so, without great contention or randomized clinical trials, it's eucalyptus leaves all around.

Yes, I am making the humbling point that we are creatures, too. We have a unique Homo sapien arrogance that induces us to speak of nature and ourselves as separate things. But we are a product of this world as much as any other species. And we are, indeed, a species. Differ though we may from one another, we are all substantially the same. We all stand on the same basic bedrock of biology. We are the same kind of creature as one another.

We are a species. In light of our capacity to feed essentially every other species on the planet appropriately -- how plausible is it, really, that we are as clueless as we seem about feeding ourselves?

That we do seem clueless doesn't seem to require much argument. First, there is the flagrant support of modern epidemiology. Both obesity and diet-related chronic disease are rampant, suggesting we either don't know what we're doing, or don't do what we're knowing. Second, search for dietary guidance by any means you like and you will topple into such a vast cacophony of competing contentions that it makes the vituperative U.S. Congress seem like the Vienna Boys Choir.

Folks, believe it or not, we are not clueless about the basic care and feeding of Homo sapiens. We are not hopelessly lost and confused, despite the popular diet book that blames it all on meat, competing with the popular diet book that blames it all on wheat, competing with the popular diet book that blames it on just sugar, competing with the popular diet book that says all grains suck.

Some months ago, I was privileged with an invitation to write a scholarly paper for the peer-reviewed journal, Annual Review of Public Health, entitled "Can We Say What Diet Is Best for Health?" The paper, which comes out in March, has a bibliography with 167 entries, representing a wide array of sources about diverse diets, reviewed with an earnest attempt at dispassionate objectivity. Even this long list of citations is a drop in the proverbial bucket, and is truncated at 167 because the journal had no space for more. I, along with a team of assistants, am now nearing completion of the third edition of my nutrition textbook for health professionals, Nutrition in Clinical Practice, and that source will have between 7,000 and 10,000 references, all in service of the same goal: establishing the facts about diet and health.

Those facts, derived from modern research, historical experience and evolutionary biology alike all support a clearly established theme of healthful eating for Homo sapiens rather well expressed by Michael Pollan as: "Eat food. Not too much. Mostly plants." With stunning consistency, a vast literature exploring diverse cultures, dietary patterns, and health outcomes, returns again and again to this theme. Off the reservation are highly processed, glow-in-the-dark foods. Always on are vegetables, fruits, beans, legumes, nuts and seeds. Almost universal are whole grains. Lean meats, fish, seafood and dairy come and go with variations on the theme, but there is clearly room for them for those so inclined.

In fact, it's a beautifully commodious scenario. The basic theme of optimal eating is quite clearly established, while the best variant on that theme most certainly is not -- leaving each of us where we belong, holding the oven mitt. Variations on the theme allow us to invoke the common principles of healthful eating, while making personalized choices conducive to loving the food that loves us back. Variations on the theme readily accommodate your choice of a vegetarian, low glycemic, Mediterranean, Asian or Paleo diet.

But then how it can it be that one book so convincingly makes the case that all our ills are due to eating animals, while another vilifies sugar just as convincingly, and yet another impugns all grains? Consider that Benjamin Disraeli famously said, "There are three kinds of lies: Lies, damn lies and statistics." Distortions of the peer-reviewed literature to support any given theory about diet fall into all three categories.

To get a grip on the truth about diet and health, it requires an objective review of a vast literature. I know, because I have been obligated to do it. To substantiate a preselected gripe, however, such as "grains are the enemy," is vastly easier. There is no need to search the literature comprehensively and deal with what you find. You need only decide what you believe in advance, and select out the studies that support it -- however few they may be. It doesn't take many scientific papers to make an argument seem fully substantiated and even erudite. But what you will not know unless you search the literature comprehensively yourself is how often the six papers convincingly cited are at odds with 6,000 papers that are not. Sorry, folks, but pseudo-erudition in support of dietary nonsense really is that easy -- and while the authors are the richer, the rest of us are the poorer, fatter and sicker for it.

The immediate inducement to write this column was an interview I did recently about the most current "thank goodness I've come along to tell you that everything you ever thought you knew about nutrition and health is wrong!" diet books. Those come along often enough to keep me in a fairly constant state of nausea. I like to think I owe my stable weight and physique to my skill set for healthy living, but maybe it's really just the fact that most of the time, I'm too disgusted to eat.

Then, there's the fact that the end of this year is now imminent, and a new year, redolent with new possibilities, looms. I would like to think that this is the new year we situate ourselves sensibly among the panoply of creatures who eat as they fundamentally should. But instead, 2013 draws to a close with a whole new crop of iconoclastic dietary diatribe. So it seems the spiny anteaters won't stop rolling their eyes at us any time soon.

The notion that we are as clueless as we generally seem about the basic care and feeding of Homo sapiens is implausibly far-fetched and, in a word, baloney. And, frankly, most of the strident, mutually-exclusive, my-theory-can-beat-your-theory, scapegoat-blaming, silver-bullet proclaiming contenders for popular diet du jour are baloney, too.

And perhaps that explains everything. We can't think straight about what to feed ourselves because we are all suffering the bloat and cognitive impairment of baloney overdose. We don't need much of a clue about what our diet ought to be to know it should be something other than this.

-fin

In his new book, DISEASE PROOF, Dr. Katz shares a practical, objective, evidence-based, view-from-altitude, ideology-free, no-spiny-anteaters-were-harmed-in-the-making-of-this-book approach to better health and lifelong weight control. DISEASE PROOF is available in bookstores nationwide and at:

Dr. David L. Katz; www.davidkatzmd.com

www.turnthetidefoundation.org

http://www.facebook.com/pages/Dr-David-L-Katz/114690721876253

http://twitter.com/DrDavidKatz

http://www.linkedin.com/pub/david-l-katz-md-mph/7/866/479/