A global consensus on lifestyle as medicine.
Why ‘No Two Nutritionists Agree’ is a Myth
Contrary to what fad diet books would have you believe, most experts agree on the basic tenets of a healthy diet.
U.S. News & World Report
April 27, 2015

I have taken care of patients now for a span of roughly 25 years. Patient care is a unique window to what the world is thinking. As people open up about the intimate details of their lives, necessary to inform good clinical decisions, their perspectives, preferences and priorities about everything from politics to religion tend to spill along with the other beans. To the extent that a given population of patients is a cross section, you can learn what the world is really thinking.

My patients think no two nutritionists agree about anything; I’ve heard it more times than I can recall. They also think no given nutrition expert holds the same opinion for more than 20 minutes at a stretch. (The latter, of course, only pertains to new patients who haven’t seen me twice, at least 20 minutes apart.)

I think these views do reflect the world at large because I have heard them elsewhere. I’ve heard them from students, audience members, email correspondents, social media contacts and even colleagues. This, then, seems to be the prevailing perception.

It is entirely false. We’ll come back to that.

There is good reason for thinking it’s true, and that reason runs on the usual fuel: money. If at any point our culture were to settle down and do what all the Blue Zone populations do – just eat wholesome foods in sensible combinations, generation after generation – whole industries would wither. What, then, of the booming fad diet book industry? Obsolete. What, then, of the ever-titillating morning show segments about the best new ways to lose weight fast? Obsolete, in part because hardly anybody would need to lose weight in the first place.

What of the monthly magazine features that, remarkably, keep inventing brand new ways for women to tone their buns, and men to get six-packs? Well, maybe those could stay – but I rather doubt it. If everyone were well-informed and fundamentally sensible about the short list of lifestyle factors, including diet, that sculpt health itself, I think they would tend to be a bit less gullible and desperate for unlikely innovations in body sculpting. (For what it’s worth, guys, the six-pack thing pretty much involves eating right and working out every day of your life! If you really do find an alternative, let me know.)

What of lotions, potions and pixie dust for losing weight, or preserving youth? All pretty much yesterday’s news.

So there are whole industries dependent on us being perennially befuddled about the basic care and feeding of Homo sapiens. Any wonder, then, we seem to be just that?

As for the authors of those fad diet books, and guest experts on those morning show segments, yes – they are complicit in this. Some of them are true renegades, radicals, wingnuts or mercenaries, too. But for the most part, they are simply playing the only game in town. However much they may agree with all of their colleagues, the only way to get any prime time attention is to focus on the disagreement. Discord is interesting. Accord, it seems, however much more empowering, is less so – at least to the producers running the show(s).

In fact, given the rules of the game, the formula for a best-selling book about diet is pretty much just that: a formula. My colleague, Dr. James Hamblin, a senior editor at The Atlantic, described it all quite aptly when we spoke together at a conference some months ago. It’s something like: lay claim to a revelation; cite the literature selectively to back up your argument; ignore all evidence to the contrary; offer up a scapegoat, silver bullet or both; and whatever you do, don’t say that the only way to get the benefits of eating well and exercising is by eating well and exercising. Oh, and be sure to throw everyone who came before you under the bus!

And then, repeat – endlessly.

Of course, it’s not just the authors and publishers and producers who benefit from this repetitive, historical folly. This whole boondoggle is a cash cow for the lipstick-on-a-pig segment of the food industry, if I may mix agrarian metaphors.

There’s been a whole lot of noise lately about how food experts have gotten our dietary advice wrong over time, time and again. But Ancel Keys never said to eat Snackwell cookies! When he and his contemporaries first recommended eating a lower-fat diet, the only way to do that was to eat more naturally low-fat foods, e.g., vegetables, fruits, beans, lentils and whole grains. Had we ever done that, all would have been well, as those remain staples in all of the world’s most healthful diets.

But we didn’t do any such thing. Ushering in the age of nutrition-for-nitwits, we pretended, at the invitation of Big Food, that as long as a food was “low-fat,” it must be a good idea – no matter the junk from which it was composed. We did the same when we cut carbs, saturated fat and high-fructose corn syrup. These days, there is a cottage industry in gluten-free junk food. Coming soon? A whole new inventory of “non-GMO” junk. Tell them what they’ve won, Johnny!

A new way of eating badly; again, and again, and again.

So it’s time to fix all this, because at stake is not just our own health – but a potentially blighted future, bequeathed to our children and grandchildren. A future in which we remain forever naïve and perennially befuddled about the basic care and feeding of Homo sapiens. A future in which every false promise or sprinkle of pixie dust has us reaching for our credit cards. And a future in which the prize for being so utterly fatuous is being fat, and sick into the bargain.

We are staring down the barrel of a gun at a future in which up to 40 percent of Americans arediabetic, and when that day comes, those “Americans” will be our children, grown up into that blighted future we devised for them.


The notion that no two nutrition experts agree is, simply, false. The notion that expert opinion in nutrition changes constantly is equally false. It evolves, of course, as science requires; but the truly good advice to eat foods close to nature, consume more plants and avoid excesses of added sugar or manufacturing mischief in general goes back decades. What we know best has stood the test of time.

Yes, I have proof of all this. Over the past 25 years, doing what I do, I have come to know many of the world’s experts and influencers in the nutrition space. I have shared meals with most of them at one time or another. And however opposed they may seem, even from the apparent extremes of vegan topaleo, my impression has long been that we all eat and behave more like one another – with our own health, and the health of those we love on the line – than any of us eats and behaves like the “typical” American.

If we could convey that consensus, we might welcome a day in the U.S. when it is impossible to sell the next fad diet book because everyone just rolls their eyes. We already know what healthy eating is! You can’t fool us anymore.

Let’s make that today. The Council of Directors of the True Health Coalition, only recently established, is already home to over 150 leading experts and influencers in diet and health from 20 countries around the world. The council can proudly claim two former U.S. surgeons general; a former commissioner of the U.S. Food and Drug Administration; chairs of nutrition departments and deans of nutrition at our most illustrious academies; leading experts in sustainable eating; and some of the world’s great culinary experts, including one who until very recently did most of his traveling aboard Air Force One. And perhaps more impressively, the very same council can proudly claim some of the world’s leading advocates of vegan eating, and some of the world’s leading advocates of paleo eating, willing to say publicly: Even we agree more than we disagree.

These colleagues are joining with me, and one another, to propagate a larger, more lasting and vastly more empowering truth about diet and health than any narrow theory on the best-seller list. A truth addressed quite well by Michael Pollan; a truth Frank Hu and I captured fairly well, if I may say; a truth well represented in the 2015 Dietary Guidelines Advisory Committee report; a truth substantiated by a truly impressive expanse of scientific evidence; a truth effective in the real world, under diverse circumstances, in fostering the enviable health of whole populations.

The idea that no two nutritionists agree, and that basic understanding of nutrition changes every 20 minutes is myth, propagated for profit.

There is a massive, global consensus among experts about the fundamentals of eating well. It’s time you knew – that you and your family may be the ones, at last, to profit – from the truth.


  • David L. Katz, MD, MPH, FACPM, FACP, is the founding director of Yale University’s Prevention Research Center; President of the American College of Lifestyle Medicine; Editor-in-Chief of the journal, Childhood Obesity; Chief Science Officer for NuVal LLC; and director of the Integrative Medicine Center at Griffin Hospital. A clinician, researcher, author, inventor, journalist, and media personality, Dr. Katz is the recipient of numerous awards and recognitions, including an honorary doctoral degree; widely supported nominations for the position of U.S. Surgeon General; recognition by Greatist.com as one of the 100 most influential people in health and fitness in the world for the past 3 years; and inclusion by LinkedIN as one of the original 150 INfluencers. He has authored over 200 scientific papers and chapters, 15 books, and well over 1,000 columns and blogs- with a resulting social media following of roughly 500,000. A two-time diplomate of the American Board of Internal Medicine, and a board-certified specialist in Preventive Medicine/Public Health, he is recognized globally for expertise in nutrition, weight management and the prevention of chronic disease. Dr. Katz has delivered addresses in numerous countries on four continents, and has been acclaimed by colleagues as the “poet laureate” of health promotion.