There is a narrative, circulating for the past decade or longer, that Americans have gotten fat because of the dietary guidelines. This narrative has been circulated above all by Gary Taubes, author of Good Calories Bad Calories and other best-selling works. Gary is a masterful storyteller.
And the story he has told has echoed throughout the online nutrition world like wildfire. It is repeated by the likes of Tim Noakes, Nina Teicholz, Jason Fung, and the rest of the who’s who of low-carbohydrate dieting. Nina Teicholz, in particular, has taken Gary’s claims to an special extreme, giving many talks around the world on how the Dietary Guidelines caused the obesity pandemic. Her book, which was centered around this idea, was highly praised by both the Wall Street Journal and the Economist.
Here is a link to a popular presentation by Nina Teicholz on just this subject: https://www.dietdoctor.com/introduction-dietary-guidelines-start-obesity-epidemic
The problem? The story that Gary and Nina tell isn’t true.
Let’s dissect through the main points of this story, piece by piece.
For one, Americans never really consumed a low-fat diet, and they never followed the Dietary Guidelines to try to consume one. Here are food availability data from both the Food and Agricultural Organization and the United States Department of Agriculture.
Below is the above data, but with a breakdown for each nutrient class.
Now let’s look at percentage of fat in the diet, with cutoffs prescribed by USDA:
Indeed, if we look at total fat (the first two graphs in this article), it seems not to have decreased at all after the dietary guidelines. If we look at % fat, it decreased from 41% to 37% (in 1997), only 4% and nowhere near the value prescribed by the guidelines of 30%. Moreover, even at its lowest level of 37% in 1997, it was still higher than in 1980 when the guidelines were released. And after 1997, the absolute dietary fat intake increased to its highest ever.
That’s not all. While some claim that the food availability data presented above are flawed, the survey data present their own problems. Here are the survey data:
So far, so good. Until one plots macronutrient trends not as a percent, but as absolute grams/day:
Strange, because all we see here are an increase in intake of carbohydrate, not a reduction in fat. What could have caused this? In a recent paper, Edward Archer notes that this apparent increase might have been caused by artifact. Indeed, the methodology of the survey changed between the second and third surveys:
In addition, obesity trends also seem to contradict the claim that dietary guidelines caused the obesity epidemic. As we can see below, obesity has been steadily increasing since at least the 1880s–a century before the Dietary Guidelines.
Not unimportantly, USDA does have a food availability dataset that goes back almost this far, using a different methodology to document years prior to 1970. The parallels between the increase in obesity and this dataset are striking. (Look at the two graphs side-by-side.)
What’s more, the above graph is roughly consistent with the food availability data. If we look closer (below), we see that calories also inflect at roughly 1960–20 years before the Dietary Guidelines.
It is likely that many factors account for the recent explosion in obesity, but whatever they are, the above evidence suggests that the seeds were planted in the 1950s or 60s or even the 1870s or 80s–not the 1980s.
If you would like to read more about macronutrient trends, please see my upcoming macronutrient trend series.
But let’s get back to the question at hand.
What exactly are Americans eating today? How close are they to the Dietary Guidelines for Americans?
For instance, what percentage of Americans fail to consume the foods recommended by the Dietary Guidelines?
These values were reported in a 2010 study:
80% fail to get the recommended total fruits
75% whole fruits
89% total vegetables
96% green leafy vegetables
98% orange vegetables
61% starchy vegetables
58% other vegetables
99% whole grains
48% meat and beans
The percent of Americans consuming more than their maximum discretionary energy allowance from solid fats and added sugars?
Solid fats 95%
Added sugars 77%
How far are Americans from meeting the recommendations laid out in the actual Dietary Guidelines, on average? Data are available on this as well.
They are eating about half as many total vegetables, half fruits, adequate grains (we’ll return to this in a moment), half dairy, and generally adequate protein as recommended by the dietary guidelines:
Americans are eating a quarter of recommended dark green vegetables, a third of red and orange, a third of recommended legumes, half of starchy vegetables, and inadequate “other vegetables”:
They are overconsuming refined grains almost two-fold and consuming only about 25% of recommended unrefined grains.
Men are eating too much meat, and women have an adequate intake. Seafood is under consumed. Nut consumption is generally adequate.
Solid fats are overconsumed, while oils are underconsumed:
Added sugars are overconsumed–by between 20-80%, depending on the age group:
The average American intake of saturated fats exceeds the maximum recommended intake:
The sodium intake is double the recommended intake in many age groups:
That was from survey data. But how do the food balance data look?
Americans still consume less than half of recommended fruit, less than 70% of recommended vegetables, and half of recommended dairy:
They overconsume total grains, with most of the recent increase from corn. (Remember that they vastly underconsume whole grains, which means that these grains that they are overconsuming are refined grains.) They also over consume protein foods relative to recommendations.
Americans massively overconsume sugar, consuming almost double that recommended by the dietary guidelines:
What kinds of foods do Americans eat? According to a recent study, nearly two-thirds are ultra-processed.
What are the major sources of calories in the American diet? A 2012 study cleanly summed this up in a single table:
It is worth noting that critics often point to the large quantity of grains in the American diet as indicating that Americans are somehow following the dietary guidelines. Yet it is worth looking (again) at what kinds of carbohydrates (and grains) Americans actually eat:
Scarcely a whole grain to be found, consistent with the above 2010 paper showing that only 1% of the American population, yes 1%, consumed the recommended whole grains.
And then, it is worth looking at the guidelines themselves:
Americans are not consuming anything remotely close to what the Dietary Guidelines for Americans recommends. Suggesting otherwise—as such people as Nina Teicholz, Jason Fung, Tim Noakes, Zoe Harcombe, and many more do—is dishonest. But it’s all part of the same old game.
The purpose of making such a claim is sensationalist. It turns the diet wars into a battle of David against Goliath. Of truth-telling rebels against corrupt bureaucrats. This is the kind of story that sells. And when you need to sell a story to make a livelihood in the Internet age, it can be a very tempting story to tell indeed.
The real truth is that the self-styled truth-tellers are in fact fabulists exploiting an obesity pandemic to make money and get attention. They do not have a side of the story. They do not have an opinion informed by evidence. Theirs is not an unpopular point of view. They have simply made a career of fooling others–and some of them have even fooled their own selves.
This is not without precedent. Echo chambers and cult-like behavior are the norm in human society throughout history. Think of the entire civilizations that have fallen victim to group-think and then self-destructed. In fact, think of the first major Western such civilization: ancient Athens. Now imagine such group-think taking place among an even smaller group of people. This is exactly what has happened among this group of low-carbohydrate diet advocates. They are Athens before waging war on Syracuse. They are clueless and hopeless–yet endlessly optimistic. They can stir up great crowds. But time and again, when one takes a moment to actually scrutinize most of their claims, it is clear that they are waging wars on the flimsiest of hopes and building castles on foundations of sand.
I do not mean by this that nothing from the low-carbohydrate diet proponents is useful. Some is useful, and I wholeheartedly support that. Fortunately, what is useful has been stripped from the useless, and responsible people, some of whom I consider my teachers, are in charge of developing these ideas further to help rather than mislead patients.
It is worth noting that the major website responsible for propagating the above false claims about the dietary guidelines and many videos associated with these claims over the past 5 years–dietdoctor.com–is in fact a storefront that uses criticism and inflammatory rhetoric directed at the medical establishment as a launching point for a business worth tens of millions of dollars. Among its targets are the United States government, individual scientists, cancer research, and life-saving statin drugs. Of the latter, the website promotes individuals who claim that these drugs harm patients, while statin scientists believe that these drugs have saved the lives of hundreds of thousands or millions of people. It is hard to not notice that this overall inflammatory approach and business model eerily follows the precedent trail-blazed by anti-vaccination groups.
This does not mean that the Dietary Guidelines are without flaws. They are not. They are poorly communicated. They are technocratic and difficult to understand. They are couched in politispeak and clearly the result of a painstaking consensus process–good procedurally, but terrible science communication. They need to explicitly recommend reducing consumption of ultraprocessed foods. The USDA, whose mandate is also to promote agriculture, probably should not be in charge of formulating them.
But make no mistake about it, what is abundantly clear is this: Americans do not follow the Dietary Guidelines. Given that, it is hard to believe, as claimed by Gary Taubes and Nina Teicholz, that they caused the obesity pandemic. Diets in the wealthy world are in many ways worse than ever–by almost every metric.
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