Carbohydrates, Essential Nutrients, and Official Dietary Guidelines

“You’ll be reassured to know that you don’t have to eat carbohydrates to live. It’s not an essential nutrient.
“It’s one of the first things we learn in nutrition is what does the body not make and what you HAVE to eat.
“You won’t find carbohydrate on this list.”
~Eric Westman, There’s no such thing as an essential carbohydrate

“Carbohydrates are not essential nutrients.”
~Denise R. Ferrier, Biochemistry

“Carbohydrates are not essential nutrients.”
~Simon W. Walker, Peter Rae, Peter Ashby, & Geoffrey Beckett, Clinical Biochemistry

“Carbohydrates are not considered essential.”
~Carie Ann Braun & Cindy Miller Anderson, Pathophysiology: Functional Alterations in Human Health

“No specific carbohydrates have been identified as dietary requirements.”
~Michael Lieberman, Allan D. Marks, & Alisa Peet , Marks’ Basic Medical Biochemistry: A Clinical Approach

“In the absence of dietary carbohydrate, the body is able to synthesize glucose from lactic acid, certain amino acids and glycerol via gluconeogenesis.”
~Jim Mann & A. Stewart Truswell, Essentials of Human Nutrition

“Even when a person is completely fasting (religious reasons, medically supervised, etc.) the 130 g / day of glucose needed by the brain is made from endogenous protein and fat.
“When people are “fasting” the 12 hour period from the end of supper the night before until breakfast (“break the fast”) the next day, their brain is supplied with essential glucose! Otherwise, sleeping could be dangerous.”
~Joy Kiddie, How Much Carbohydrate is Essential in the Diet?

Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids
from National Academies of Sciences, Engineering, and Medicine
published by Institutes of Medicine
2005 textbook of the US Food and Nutrition Board

The lower limit of dietary carbohydrate compatible with life apparently is zero, provided that adequate amounts of protein and fat are consumed. However, the amount of dietary carbohydrate that provides for optimal health in humans is unknown. There are traditional populations that ingested a high fat, high protein diet containing only a minimal amount of carbohydrate for extended periods of time (Masai), and in some cases for a lifetime after infancy (Alaska and Greenland Natives, Inuits, and Pampas indigenous people) (Du Bois, 1928; Heinbecker, 1928). There was no apparent effect on health or longevity. Caucasians eating an essentially carbohydrate-free diet, resembling that of Greenland natives for a year tolerated the diet quite well. However, a detailed modern comparison with populations ingesting the majority of food energy as carbohydrate has never been done.

Why Won’t We Tell Diabetics the Truth?
by Diana Rodgers

They base the carbohydrate requirement of 87g-112 grams per day on the amount of glucose needed to avoid ketosis. They arrived at the number 100g/day to be “the amount sufficient to fuel the central nervous system without having to rely on a partial replacement of glucose by ketoacid,” and then they later say that “it should be recognized that the brain can still receive enough glucose from the metabolism of the glycerol component of fat and from the gluconeogenic amino acids in protein when a very low carbohydrate diet is consumed.” (Meaning, ketosis is NO BIG DEAL. In fact, it’s actually a good thing and is not the same as diabetic ketoacidosis that type 1 diabetics and insulin dependent type 2 diabetics can get.) The RDA of 130g/day was computed by using a CV of 15% based on the variation in brain glucose utilization and doubling it, therefore the the RDA (recommended daily allowance) for carbohydrate is 130% of the EAR (estimated average requirement).

Added sugars drive nutrient and energy deficit in obesity: a new paradigm
by James J DiNicolantonio and Amy Berger

Mankind has survived without isolated, refined sugar for almost 2.6 million years.48 The body—in particular, the brain—has been thought to require upwards of 200 g of glucose per day, leading to the often cited dogma that glucose is ‘essential for life’.1 While it is true that glucose is essential for sustaining life, there is no requirement for dietary glucose, as fatty acids can be turned into brain-fuelling ketone bodies, and amino acids and glycerol are gluconeogenic substrates.49 Indeed, in the relative absence of dietary glucose, ketone bodies may supply upwards of 75% of the brain’s required energy, with the remainder supplied by gluconeogenesis provided by amino acids (from dietary protein or catabolism of body proteins) and from glycerol (provided by the breakdown of triglycerides in adipose tissue).33 Thus, exogenous glucose (eg, from added sugars) is not essential for sustaining life in humans, and in most people, restricting dietary carbohydrates seems to produce no ill effects.49 In fact, according to the Food and Nutrition Board of the Institute of Medicine of the US National Academies of Sciences, ‘The lower limit of dietary carbohydrate compatible with life apparently is zero, provided that adequate amounts of protein and fat are consumed’.50

Administration of fructose or sucrose in humans has been shown to cause each of the abnormalities that define the metabolic syndrome (eg, elevated triglycerides, low high-density lipoprotein, insulin resistance, glucose intolerance, elevated blood glucose, elevated blood pressure and weight gain (specifically around the abdomen)),30 51–55 as well as features found in patients with coronary heart disease (eg, increased platelet adhesiveness and hyperinsulinaemia),56 57 all of which can be reversed entirely upon reverting to a diet low in sugar.47 52 56 58–60 Consumption of added sugars at current levels of intake is proposed as a contributing factor in a multitude of other diseases associated with early mortality, such as cardiometabolic disease,61–64 obesity,30 61 65–68 β-cell dysfunction and type 2 diabetes,6 20 69–71 hypertension,51 64 72 non-alcoholic fatty liver7 and atherosclerosis.6 73 74 Because of this, added sugars cannot be considered food.

What to Eat: The Ten Things You Really Need to Know to Eat Well and Be Healthy
by Luise Light, pp. 18-21, 

The alterations that were made to the new guide would be disastrous, I told my boss, the agency director. These changes would undermine the nutritional quality of eating patterns and increase risks for obesity and diabetes, among other diseases. No one needs that much bread and cereal in a day unless they are longshoremen or football players, and it would be unhealthy for the rest of us, especially people who are sedentary or genetically prone to obesity and diabetes. […]

At stake here, I told him, was nothing short of the credibility and integrity of the USDA as a source of reliable nutrition information. Over my objections, the alterations were included and the guide was finalized. I was told this was done in order to keep the lid on the costs of the food stamp program. Fruits and vegetables were expensive, much more expensive than breads and cereals, and the added servings of grains would, to some extent, offset the loss of nutrients from fruits and vegetables, the head of our division told me. However, the logic of that rationale escaped me.

Refined wheat products are what we called in the nutrition trade “cheap carbos,” stomach-filling food preferred when other, higher quality foods are unavailable or not affordable. They do little—if anything—to boost the nutritional quality of people’s diets and tend to add not only starch, but also fat and sugar to the diet. It was curious that there had been no discussion of the cost constraints of the food stamp program in any previous discussion over the many months we had been working on the guide. Intuitively, I knew I was being “played,” but other than stalling and requesting additional outside reviews I felt stymied.

Later, I remembered a Pan American Health Organization (PAHO) nutrition survey I had participated in during graduate school. One of our findings was a high rate of obesity among women in a particular region of the Caribbean country we were working in that had the lowest employment and per capita income. It puzzled me that the poorest region would have the most obese people until one of the physicians on our team explained that the prevalence of obesity was consistent with what he called an “impoverished diet,” too little nutritious food that caused people to feel hungry all the time, and with only cheap carbohydrates available to them, their hunger was never appeased, so they ate and ate and became fatter and fatter.

Was this inflated grain recommendation, I wondered, setting us up for a third world obesity scenario in our own country? Historically, the food guide was used to calculate the cost basis of the food stamps program. Did that mean we needed to develop two different sets of standards for nutrition, one for poor people and another for those better off, or did it mean that what was affordable in the food stamps program would determine what was best for the rest of us? Neither of these Hobson’s choices could be justified on scientific or ethical grounds. The changes that were made to the guide meant that any food product containing wheat flour, from white bread, Twinkies, Oreos, and bagels to pop toasters and Reese’s Puffs, would be considered nutritionally equivalent, which was not the case.

With my protests falling on deaf ears, the serving suggestions in the revised guide were incorporated into the regulations for the food stamps program, as well as the school breakfast and lunch, day care, and all other feeding programs administered by the USDA. Later, Congress set the serving amounts into legislative “stone” so it would be against the law not to serve the expanded number of grain servings that were in the new guide, a change that meant a financial windfall for the wheat industry. The new rules for school lunch programs increased the amount of bread and cereal products purchased for the program by 80 percent. For children in grades K through six, it meant eight daily servings of breads, cereals, and pasta, and for grades seven through twelve, ten servings.

For wheat growers, this meant an increase of 15 million bushels of wheat sold annually worth about $50 million and a retail sales boost of $350 million from additional sales of cereals, breads, and snacks. That didn’t include the extra sales resulting from the government subsidized food stamps program or revenues from the industry’s own efforts to shift public consumption toward more bread, pasta, and baked goods because of the new recommendations. Throughout the nineties, Americans increased their consumption of refined grain products from record lows in the 1970s to the six to eleven servings suggested in the new guide.

* * *

Partial credit for some of the quoted material goes to Bill Murrin, from comments he left at the article Dietary guidelines shouldn’t be this controversial; published at Marion Nestle’s website, Food Politics.

2020 Dietary Guidelines: Fight Over Low-Carb

The HHS and USDA put out new U.S. dietary guidelines every 5 years. They are having discussions now. There recently was allowed for various interests to speak. Several of the speakers were were promoting low-carb diets.

I doubt low-carb advocates will get a fair hearing after a half century of political suppression. But at least they are no longer being silenced. Being part of the conversation is the first step. They are at least being acknowledged now.

Too many Americans are changing their lives with low-carb. It can’t be ignored any more.

42:10 Priyanka Wali, MD – (Commenter 13)
1:25:20 Nina Teicholz (Commenter 28)
2:53:25 Georgia Ede, MD (Commenter 54)
3:16:26 Sarah Hallberg, MD (Commenter 64)

The 2020 Dietary Guidelines for Americans:
Ensuring that Science is the Main Ingredient
from Union of Concerned Scientists

The Snack Food and Corn Syrup Lobbyist Shaping Trump’s Dietary Guidelines for Americans
by Laura Peterson

Food Companies at the Table in Trump Administration’s Dietary Guidelines Committee
by Derrick Z. Jackson

Diets are not one-size-fits-all. So why do we treat dietary guidelines that way?
by Nina Teicholz

Dietary Guidelines 2020: The low-carb debate
by Helena Bottemiller Evich

Dietary guidelines advisory panel to tackle carbs in 2020-2025 recommendations
by Steve Davies (Google cache)

Low-Carb Diets On The Rise
American Diabetes Association Changes Its Tune
Slow, Quiet, and Reluctant Changes to Official Dietary Guidelines
Official Guidelines For Low-Carb Diet
Obese Military?
The Creed of Ancel Keys
Cold War Silencing of Science
Eliminating Dietary Dissent
Dietary Dictocrats of EAT-Lancet
Highly Profitable Conflicts of Interest

Corporate Media Slowly Catching Up With Nutritional Studies

“The change in dietary advice to promote low-fat foods is perhaps the biggest mistake in modern medical history.”
 ~ Dr. Aseem Malhotra, cardiologist and expert on heart disease

“Fundamental problems were 2-fold. First, acceptance of weak associational epidemiological data as proof of causation. Second promotion of diet-heart hypothesis/lo fat diet to the public ahead of definitive proof of outcomes. Diet-heart hypothesis then became incontestable dogma.”
~ Tim Noakes, emeritus professor, scientist, and expert on low-carb diets

We’re All Guinea Pigs in a Failed Decades-Long Diet Experiment
by Markham Heid, Vice

The US Department of Agriculture, along with the agency that is now called Health and Human Services, first released a set of national dietary guidelines back in 1980. That 20-page booklet trained its focus primarily on three health villains: fat, saturated fat, and cholesterol.

Recently, research has come out strongly in support of dietary fat and cholesterol as benign, rather than harmful, additions to person’s diet. Saturated fat seems poised for a similar pardon.

“The science that these guidelines were based on was wrong,” Robert Lustig, a neuroendocrinologist at the University of California, San Francisco, told VICE. In particular, the idea that cutting fat from a person’s diet would offer some health benefit was never backed by hard evidence, Lustig said.

Just this week, some of Lustig’s colleagues at UCSF released an incendiary report revealing that in the 1960s, sugar industry lobbyists funded research that linked heart disease to fat and cholesterol while downplaying evidence that sugar was the real killer.

Nina Teicholz, a science journalist and author of the The Big Fat Surprise, said a lot of the early anti-fat push came from the American Heart Association (AHA), which based its anti-fat stance on the fact that fat is roughly twice as calorie-dense as protein and carbohydrates.

“[The AHA] had no clinical data to show that a low-fat diet alone would help with obesity or heart disease,” Teicholz told VICE. But because fat was high in calories, they adopted this anti-fat position, and the government followed their lead. Surely the 1960s research rigged by the Sugar Association, which was published in the prestigious New England Journal of Medicine, added to our collective fat fears.

By the 1990s, when Teicholz says the epidemiological data started piling up to show that a low-fat, high-carb diet did not help with weight loss or heart disease—calories be damned—much of the damage was already done. The US public was deep in what nutrition experts sometimes call the “Snackwell phenomenon”—a devotion to low-fat and low-calorie processed snack foods, which people pounded by the bagful because they believed them to be healthy.

“This advice [to avoid fat] allowed the food industry to go hog-wild promoting low-fat, carb-heavy packaged foods as ‘light’ or ‘healthy,’ and that’s been a disaster for public health,” Lustig said.

The stats back him up. Since the US government first published a set of national nutrition guidelines in 1980, rates of obesity and related diseases like diabetes have more than doubled. “Childhood diabetes was basically unheard of, and now it’s an epidemic,” Lustig said.

Overseas, national health authorities followed America’s lead on fat. The results have been similarly grim. Earlier this year, a UK nonprofit called the National Obesity Forum (NOF) published a blistering condemnation of its government’s diet and nutrition policies. […]

Teicholz said it’s hard to overstate the effect of national health authorities’ pro-carb, anti-fat stance. A whole generation of health professionals accepted—and passed on to their patients—the government’s guidance to avoid fat and cholesterol. Many still do.

“Both professional and institutional credibility are at stake,” she said when asked why more doctors and policymakers aren’t making noise about the harms caused by the government’s dietary guidance. She also mentioned food industry interests, the potential for “massive class-action lawsuits,” and the shame of copping to nearly a half-century of bad diet advice as deterrents for USDA and other health authorities when it comes to admitting they were wrong. […]

But one thing is clear: Dietary fat was never the boogeyman health authorities made it out to be.

“I think most of us would be 90 percent of the way to a really healthy diet if we just cut out processed foods,” UCSF’s Lustig said. “We wouldn’t need diet guidelines if we ate real food.”

Slow, Quiet, and Reluctant Changes to Official Dietary Guidelines

Nourishment
by Fred Provenza
pp. 236-237

In 2015, the Dietary Guidelines Advisory Committee (DGAC) issued a report with a striking recommendation: Eliminate dietary cholesterol as a nutrient of concern. This change astonished the public but is consistent with scientific evidence reporting no appreciable relationship between dietary cholesterol and serum cholesterol or clinical cardiovascular events in general populations. A less obvious change was the absence of an upper limit on total fat consumption. With this report, the DGAC reversed nearly four decades of nutrition policy that placed priority on reducing cholesterol and total fat consumption throughout the population. As with other scientific fields from physics to clinical medicine, scientists contend understanding of nutrition has advanced in recent decades.

Yet, despite the apparent increase in understanding obesity and diet-related diseases continue to rise. In 1960, fewer than 13 percent of Americans were obese, and fewer than 1,100 scientific articles were published on obesity and diabetes. Today, 49 percent of Americans are obese and the United States ranks number one among thirty-five nations in childhood obesity. In 2013, 44,000 scientific articles were published on these topics. In total, over 600,000 articles have been published alleging to provide worthwhile information on diet-related disorders.

The Government’s Bad Diet Advice
by Nina Teicholz

FOR two generations, Americans ate fewer eggs and other animal products because policy makers told them that fat and cholesterol were bad for their health. Now both dogmas have been debunked in quick succession.

First, last fall, experts on the committee that develops the country’s dietary guidelines acknowledged that they had ditched the low-fat diet. On Thursday, that committee’s report was released, with an even bigger change: It lifted the longstanding caps on dietary cholesterol, saying there was “no appreciable relationship” between dietary cholesterol and blood cholesterol. Americans, it seems, had needlessly been avoiding egg yolks, liver and shellfish for decades. The new guidelines, the first to be issued in five years, will influence everything from school lunches to doctors’ dieting advice. […]

In 2013, government advice to reduce salt intake (which remains in the current report) was contradicted by an authoritative Institute of Medicine study. And several recent meta-analyses have cast serious doubt on whether saturated fats are linked to heart disease, as the dietary guidelines continue to assert.

Uncertain science should no longer guide our nutrition policy. Indeed, cutting fat and cholesterol, as Americans have conscientiously done, may have even worsened our health. In clearing our plates of meat and eggs (fat and protein), we ate more grains, pasta and starchy vegetables (carbohydrates). Over the past 50 years, we cut fat intake by 25 percent and increased carbohydrates by more than 30 percent, according to a new analysis of government data. Yet recent science has increasingly shown that a high-carb diet rich in sugar and refined grains increases the risk of obesity, diabetes and heart disease — much more so than a diet high in fat and cholesterol.

My Beef With The AHA’s Saturated Fat Recommendations
by Larry Husten

Reading the new AHA paper I was struck by its extreme self-confidence, paralleled by its unwillingness to acknowledge the disastrous consequences of the last time the AHA pushed back against dietary fat and cholesterol. The result, as we all should know by now, was to unwittingly help unleash or at least contribute to the obesity and diabetes epidemics, as saturated fat and dietary cholesterol were replaced by carbs, often refined carbs, and sugar. Notably, the AHA took a long time to change its guidelines, and when it did those efforts were far less aggressive and received far less publicity than the original campaigns.

Now the memory of that catastrophe is fading, at least in some people who would rather forget it. In an article in Medscape one nutrition expert, defending the new AHA paper, offered the following quote: “But the AHA has always taken the stance that saturated fat is bad and that we should be eating more plant oils, and this view is endorsed by the vast majority of nutritionists who are scientifically qualified. [emphasis added]” He’s already forgotten that, in fact, in its earlier campaign the AHA did not explain that saturated fat should not be replaced with carbs, or even sugar.

Government revises Dietary Guidelines for Americans: Go ahead and have some eggs
by Peter Whoriskey

The federal government on Thursday told Americans not to worry so much about cholesterol in their diets, that lots of coffee is fine and that skipping breakfast is no longer considered a health hazard.

The recommendations were part of a new “Dietary Guidelines for Americans,” the influential nutrition advice book that, updated every five years, expresses official thinking about what constitutes a nutritious meal.

In what may be the most striking change, the new version drops the strict limit on dietary cholesterol, stepping back from one of most prominent public health messages since the ’60s.

But there were several other notable changes. Salt limits were eased, if only slightly, for many people. Coffee won official approval for the first time, with the book saying that as many as five eight-ounce cups a day is fine. And apparently, skipping breakfast is no longer considered a health hazard: While the old version of Dietary Guidelines informed readers that “not eating breakfast has been associated with excess body weight,” the new version is silent on the topic. […]

Nevertheless, the new version seems inconsistent in places, or torn between new science and past recommendations.

For example, the new document dropped the warning about dietary cholesterol from its key recommendations and the document no longer calls for people to limit their cholesterol intake to 300 milligrams per day. This change was recommended by its own expert committee, which found that cholesterol is no longer “a nutrient of concern.”

But elsewhere in the report, the guidelines cite a 16-year-old report from the Institute of Medicine and advises people to “eat as little dietary cholesterol as possible while consuming a healthy eating pattern.”

Similarly, the report calls for people to limit the amount of saturated fat in their diet to 10 percent of their calories, and accordingly to choose milk and other dairy products that are no-fat or low-fat. But newer research, also cited by the guidelines, shows that merely reducing consumption of saturated fats may offer no benefit if people merely replace those saturated fats with carbohydrates, as they often do. […]

For all the debate, whether the guidelines have made American healthier is also a matter of debate. Critics have faulted the guidelines for failing to prevent the nation’s epidemic of obesity, and say major changes are necessary in the advice given.

“Given the same advice, it’s not clear why we should expect different outcomes, especially when consumption data shows that over the past decades, Americans have, in fact, followed USDA advice,” said Nina Teicholz, the author of Big Fat Surprise and a board member at the Nutrition Coalition, a new group, funded by Houston-based philanthropists Laura and John D. Arnold, lobbying for changes to the way the government develops dietary advice.

American Heart Association doubles down on outmoded saturated fat
by Dr. Ronald Hoffman

Are you suffering from health news whiplash? It seems lately that all the news has been about the how saturated fats have been exonerated—studies show that meat and high fat dairy contribute negligibly or not at all to the risk of heart disease.

In the face of all this new evidence, I’ve railed against the American Heart Association’s obdurate refusal to acknowledge that they were wrong. They continue to maintain, on their website and through their public pronouncements, that consumers should curtail their consumption of saturated fats and substitute instead polyunsaturated oils—corn, soy, and safflower.

A recent National Institutes of Health reviewshattered that premise: It showed that by swapping dietary saturated fats with vegetable oils, subjects indeed lowered their cholesterol. But that cholesterol reduction didn’t translate into protection against atherosclerosis, heart attacks or death from all causes.

But last week, to my astonishment, the American Heart Association reiterated its position: Its “Presidential Advisory on Dietary Fats and Cardiovascular Disease” states “Lower intake of saturated fat and coupled with higher intake of polyunsaturated and monounsaturated fat is associated with lower rates of cardiovascular disease and of other major causes of death and all-cause mortality.” The magnitude of this protective effect is estimated to be a whopping 30%, comparable to the use of statin drugs [irony intended!].

This is reminiscent of the way a religious orthodoxy, whose authority might be threatened with facts that undermine its cherished dogma, would fight back with renewed vigor: Science declares, “The earth is round.” Counter this heresy by delivering a pronouncement that, indeed, the earth is flat. Order it proclaimed from every pulpit.

New AHA report, but same old dogma
by Dr. Bret Scher

On the whole, this report seems like a great summary of how science exonerates dietary cholesterol from increasing heart disease risk.

And this is where I get lost. I need someone to please explain to me how they reached their conclusion that, based on their science advisory, the AHA recommends:

“… consumers are advised to eat a dietary pattern characterized by fruits, vegetables, whole grains, low-fat or fat-free dairy products, lean protein sources, nuts, seeds, and vegetable oils, consistent with those recommended in the 2015 to 2020 DGA. These patterns have a relatively high ratio of polyunsaturated fatty acid to saturated fatty acid and are low in cholesterol, achieved by minimizing the intake of major sources of saturated fat intake (animal fats) and including liquid non-tropical vegetable oils. Choosing plant-based protein sources will limit cholesterol intake.”

The conclusion is a complete disconnect from the science the report presents. What started as a “science” update turned into an opinion piece that disregards the science just presented. That is what I expect to see on Netflix documentaries, but I expect more from a scientific organization such as the AHA.

At Diet Doctor we will continue to call out these dangerous discrepancies. Organizations should not be able to espouse their opinion and masquerade it as science.

The Big Fat Surprise
by Nina Teicholz
pp. 184-185

Taken together, these trials have shown that the low-fat diet has at best proved ineffective against disease and at worst aggravated the risk for heart disease, diabetes, and obesity. The standard, AHA-prescribed low-fat diet has consistently failed to produce better results for health than diets higher in fat.

A review in 2008 of all studies of the low-fat diet by the United Nation’s Food and Agriculture Organization concluded that there is “no probable or convincing evidence” that a high level of fat in the diet causes heart disease or cancer. And in 2013 in Sweden, an expert health advisory group, after spending two years reviewing 16,000 studies, concluded that a diet low in fat was an ineffective strategy for tackling either obesity or diabetes. Therefore, the inescapable conclusion from numerous trials on this diet, altogether costing more than a billion dollars, can only be that this regime, which became our national diet before being properly tested, has almost certainly been a terrible mistake for American public health.

“It is increasingly recognized that the low-fat campaign has been based on little scientific evidence and may have caused unintended health consequences,” wrote Frank Hu, a nutrition professor at the Harvard School of Public Health, in 2001. With this growing pile of evidence on the table, health authorities clearly see the need to update their advice. Yet they are understandably reluctant to reverse course too loudly on fifty years of nutrition recommendations, and this hesitance has led to a certain vagueness on the subject. The USDA and AHA have both quietly eliminated any specific percent fat targets from their most recent lists of dietary guidelines. Those 30–35 percent fat targets that we’ve abided by for decades? They’re now gone. And so is, actually, any discussion of the topic in their reports. How much fat should we be eating? These groups now don’t say, and this silence on the issue—it must be said—does not seem like the clear, confident leadership from our authorities that we might like to see on the subject of how we should eat to fight the major diseases of our time.

Of course many of us who’ve been paying attention to the science have been welcoming fat back into our diets for some time already. We’ve given up spraying with Pam, stopped poaching, and started using salad dressings again. And if there’s a silver lining to those low-fat years, it’s this: we learned that fat is the soul of flavor. Food is tasteless and cooking nearly impossible without fat. Fat is essential in the kitchen to produce crispness and to thicken sauces. It is crucial in conveying flavors. It makes baked goods flaky, moist, and light. And fat has many other, essential functions in cooking and baking. To satisfy all these compelling needs, nutrition experts coming out of the low- to nonfat 1980s and looking for a solution found one apparently perfect candidate: olive oil. And that is one of the reasons why, in the early 1990s, the “Mediterranean Diet” entered the picture.

pp. 339-342

Americans have dutifully followed official dietary advice to restrict fat and animal products for more than sixty years now, ever since the AHA first recommended this diet in 1961 as the best way to avoid heart disease and obesity. Nineteen years later, in 1980, the USDA guidelines joined in. Since then, the government’s own data shows that Americans have reduced their consumption of saturated fat by 11 percent and overall fat by 5 percent. XXXIV Red meat consumption has steadily declined, replaced by chicken. According to a USDA report, Americans also complied with official advice to lower the dietary cholesterol found abundantly in egg yolks and shellfish, even though the cholesterol in food has long been known to have little impact on serum cholesterol (as discussed in Chapter 2). XXXV The original rationale for cutting back on fat was to lower serum cholesterol, and Americans have successfully done that, too. Since 1978, total cholesterol levels among US adults have fallen from an average of 213 mg/dL down to 203 mg/dL. The portion of Americans with “high” cholesterol (over 240 mg/dL) has dropped from 26 percent to 19 percent. Moreover, most of that drop has been due to declines in LDL-cholesterol, the target most emphasized by officials for the past thirty years. In 1952, when Ancel Keys first started arguing for the reduced-fat diet, he predicted that if “mankind stopped eating eggs, dairy products, meats and all visible fats,” heart disease would “become very rare.” This has certainly not been the case.

Indeed, during these years, and despite or perhaps because of these efforts, Americans have experienced skyrocketing epidemics of obesity and diabetes, and the CDC estimates that 75 million Americans now have metabolic syndrome, a disorder of fat metabolism that, if anything, is ameliorated by eating more saturated fat to raise HDL-cholesterol. And although deaths from heart disease have gone down since the 1960s, no doubt due to improved medical treatment, it’s not clear that the actual occurrence of heart disease has declined much during that time.

Authorities are naturally reluctant to take responsibility for this outcome. The same recent USDA report that documents the public’s success in adhering to its dietary guidelines nevertheless places the onus of blame for obesity and disease squarely on American children and adults, “very few” of whom “currently follow the US Dietary Guidelines”—an unsubstantiated assertion that is repeated throughout the report.

The dietary recommendations now offered by the USDA and AHA for solving the nation’s health problems are basically: stay the course. Both groups have backed off their limits on fat slightly. The most recent set of AHA dietary guidelines shifts its dietary fat recommendation from a limit of 30 percent of calories to a range of between 25 percent and 35 percent, arguably a meaningless change to most people. And the USDA’s latest Dietary Guidelines, published in 2010, scrapped any specific percentile targets for the three main macronutrient groups, protein, fat, and carbohydrates, altogether. XXXVI Yet the prohibitions against saturated fats remain strong, and the USDA report continues to take the stance that “healthy diets are high in carbohydrates.”

Meanwhile, the same biases that have sustained the diet-heart hypothesis for so many decades remain, and those biases continue to steer the nutrition conversation every step of the way. So, in 2006, when the Women’s Health Initiative reported that a low-fat diet made no difference to disease or obesity, the WHI investigators, as well as officials at the AHA and NHLBI, issued press releases stating that this half-a-billion-dollar study had not been conducted well enough to make any conclusions about changing our diets. In 2010, when Krauss’s metanalysis came out with good news about saturated fats, the American Journal of Clinical Nutrition minimized its impact by publishing the critical editorial by Jerry Stamler as an “introduction” to Krauss’s work. And inconvenient findings, such as those by Volek and Westman, continue to be ignored, reasoned away, or misinterpreted by the great majority of nutrition experts.

Moreover, the alliance between the media and the nutrition mainstream endures. Mark Bittman, a food columnist at the New York Times , is perhaps the most prominent example of a voice in the media encouraging a diet based on fruits and vegetables while minimizing meat, a mantle he inherited from Jane Brody. Journalists and nutrition authorities also continue to dovetail in amplifying any study finding that appears to condemn either red meat or saturated fat. XXXVII And the public gets the message. Americans continue to avoid all fats: the market for “fat replacers,” the foodlike substances substituting for fats in processed foods, was, in 2012, still growing at nearly 6 percent per year, with the most common fat replacers being carbohydrate-based. XXXVIII

If, in recommending that Americans avoid meat, cheese, milk, cream, butter, eggs, and the rest, it turns out that nutrition experts made a mistake, it will have been a monumental one. Measured just by death and disease, and not including the millions of lives derailed by excess weight and obesity, it’s very possible that the course of nutrition advice over the past sixty years has taken an unparalleled toll on human history. It now appears that since 1961, the entire American population has, indeed, been subjected to a mass experiment, and the results have clearly been a failure. Every reliable indicator of good health is worsened by a low-fat diet. Whereas diets high in fat have been shown, again and again, in a large body of clinical trials, to lead to improved measures for heart disease, blood pressure, and diabetes, and are better for weight loss. Moreover, it’s clear that the original case against saturated fats was based on faulty evidence and has, over the last decade, fallen apart. Despite more than two billion dollars in public money spent trying to prove that lowering saturated fat will prevent heart attacks, the diet-heart hypothesis has not held up.

In the end, what we believe to be true—our conventional wisdom—is really nothing more than sixty years of misconceived nutrition research. Before 1961, there were our ancestors, with their recipes. And before them, there were their ancestors, with their hunting bows or traps or livestock—but like lost languages, lost skills, and lost songs, it takes only a few generations to forget.

* * *

For more info, see:

Official Guidelines For Low-Carb Diet
American Diabetes Association Changes Its Tune
American Heart Association’s “Fat and Cholesterol Counter” (1991)