By Dr. Mercola
The 2015-2020 U.S. Dietary Guidelines were recently published,1
and while they include some positive changes, they still contain
serious flaws as well. In this interview, Nina Teicholz reviews a number
of them—a task for which she is particularly suited, considering she’s
read the entire 571-page guidance report.
Teicholz is an investigative journalist and the author of the New York Times bestseller “The Big Fat Surprise: Why Butter, Meat & Cheese Belong in a Healthy Diet.” I previously interviewed her about that book, which delves deep into the topic of healthy versus unhealthy fats.
So, why should you care about the U.S. dietary guidelines? “They don’t affect me,” you might think.
“Here’s why they matter,” Teicholz says. “They determine
what foods are in the feeding assistance programs run by the US
Department of Agriculture (USDA) that touch 1 in 4 Americans every
month.
Those include the National School Lunch Program (NSLP) (for many
people the food that their kids are getting at school), programs for the
elderly, Supplemental Nutrition Assistance Program (SNAP)...and
military rations.”
Dietary Guidelines Dictate What Many Americans Eat Every Day
So while you may not peruse the dietary guidelines to influence your
own eating habits, they end up directly influencing the diets of many
Americans, including those with the least means to take control over
their own food choices, such as those depending on food programs for
their daily meals.
Moreover, when you go to your doctor, your nutritionist or dietician,
the nutritional recommendations you’ll get are largely based on the
dietary guidelines. If following the guidelines increases your risk of health problems, then seeking professional guidance certainly doesn’t do much good.
The guidelines even have international ramifications, as nations that
don’t have the resources and scientific expertise to duplicate the
process simply model their own guidance after the U.S.
The rest of the world really looks to the United States as a leader
in this area, even though it’s readily apparent that the guidelines must
be seriously flawed in some way, since they don’t produce very good
results.
Even international organizations like the World Health Organization
(WHO) and the Food and Agriculture Organization of the United Nations
(FAO) follow, to a large extent, the nutritional guidance developed by
the U.S.
How U.S. Dietary Guidelines Gave Rise to the Obesity Epidemic
The dietary guidelines were launched in 1980. The first guidelines
were actually written by a single Senate staffer who just so happened to
be heavily influenced by certain scientists, and this first edition
laid the groundwork for what has turned into decades of flawed advice.
Nowadays, an expert panel of about 14 members is convened every five
years to review the latest evidence and make recommendations about what
should remain and what needs to be changed. Statistics reveal just how
influential these guidelines actually are.
In 1965, Americans ate about 40 percent of their calories as
carbohydrates and another 40 percent of their calories came from fat.
The original guidelines issued in 1980 called for a diet lower in fat
and higher in carbohydrates, and by 2010, Americans had indeed brought
their fat consumption down below 35 percent, and increased carbohydrates
to 55 to 65 percent.
The basic advice to eat more carbs has been followed ever since. Now
granted, you need carbs. But not all carbohydrates are equal. Fiber-rich
carbs (mostly vegetables), are essential for good health because they
break down into short-chain fatty acids in your gut, which helps make
ketones and nourish your body.
They also serve as fuel for beneficial bacteria in your colon. But
most people don’t eat vegetables; they eat processed carbs like grains,
pasta, rice, potatoes and other starchy vegetables.
As shown in the following graph,2
fruit and vegetable consumption is trailing far behind grains, having
increased only slightly since 1970, whereas grain consumption has seen
the largest increase.
Fiber Versus Non-Fiber Carbs — An Important Distinction That Can Improve Your Health
I believe most people benefit by restricting the net carbs to less than 50 grams per day (i.e. total carbs minus fiber). Subtract the fiber from the total carbs, and that’s your total non-fiber carbs.
For most people, it would be a good idea to limit that to 50 grams a
day. If you exercise a lot and are particularly active, you might be
able to increase it to 100 grams.
Ultimately, whether it’s whole grain, refined grain, or sugar, it
boils down to the same question: Does it contain fiber, and if so how
much? This is the distinction that needs to be made, because until you
sufficiently restrict net carbs, you’re unlikely to see a change in
health outcomes.
“The one point to understand here is that there’s a large body of
science showing that restricting total carbohydrates is an effective
way to fight obesity, diabetes, and heart disease,” Teicholz says.
“Excessive carbohydrates, if you have too many net carbohydrates
and too little fat, that diet seems to worsen heart disease risk
factors. The shifting away from fat to carbohydrates over the last three
and a half decades is plausibly what has provoked obesity and diabetes.
In fact, there’s a very disturbing chart that shows obesity rates
in America being relatively flat and low. In the 1980’s (when the
dietary guidelines came out), they just shoot up. You could say 1980 was
really the beginning of the obesity epidemic, and thereafter the
diabetes epidemic began. There’s a plausible correlation there to
suggest that the dietary guidelines actually cause those
nutrition-related conditions.”
Two Realities That Undermine the Ability to Create Science-Based Policy
Ideally, policy should be based on the best possible science. Today,
the medical literature tells us that the low-fat diet has consistently
been proven ineffective. There are good clinical trials and metanalyses
that show saturated fats are unlikely to cause heart disease.
So why don’t the dietary guideline committees review that evidence
and change their recommendations accordingly? Teicholz believes there
are two major explanations for this:
1. There are major industry interests at
stake. The guidelines are part of the USDA, and part of the USDA’s
mission is to promote agriculture. At the same time, they have a mandate
to tell people to eat less of some foods and more of others. Those two
mandates conflict.
The food and agricultural industries also have the ability to
influence the guidelines. As it stands, the industries benefitting from
the guidelines include makers of carbohydrate-based foods, as well as
the corn and soy industries, as corn and soybean oil are used in most
processed foods.
The guidelines, which call for avoiding saturated fats, have led to a
91 percent increase in unsaturated fat consumption (mainly vegetables
oils) over the past three decades. According to Teicholz: “The
manufacturers of those are huge corporations: ADM, Unilever, Monsanto,
and Bunge, and they clearly work closely with the scientists who are
most influential over the guidelines.” 2. Another major factor that keeps the
guidelines from changing is the professional investment that has grown
out of the advice. Entire careers are at stake, should a guideline be
admitted wrong and altered too dramatically.
“Many institutions have invested in this particular hypothesis about what makes people healthy,” Teicholz says.
“The entire federal government invested in this hypothesis about what
makes people healthy. The American Heart Association (AHA).
These giant institutions cannot be seen as flip-flopping on their
public. They can’t be wrong. That prevents backing out of any advice
that might be flawed. When they do, they’re really called out on it as
they shouldn’t be. That’s embarrassing and difficult, and ultimately
erodes the public’s confidence in our institutions.”
Contradictions and Scientifically Weak Advice Abounds
The report from the expert panel is 571 pages long. Teicholz actually
read the entire report, and wrote an article about her findings for the
BMJ last year.3
She notes the panel report contains a number of contradictions and
recommendations that aren’t supported by the actual evidence. “It was
very disappointing to see that this was the document that was guiding
our national policy,” she says. Her article sparked a great deal of
controversy—so much so the BMJ eventually retracted it.
“This article [was] the first high-level critique of the way the
science is reviewed for the dietary guidelines and it makes a number of
points,” Teicholz says. “It says that some of these reviews
did not happen in a systematic way. They have their own system within
the USDA called the Nutrition Evidence Library (NEL), which is supposed
to do systematic reviews of the literature.
On a number of key topics, they did not use the Nutrition
Evidence Library... including on unsaturated fats where there’s been a
tremendous amount of new research in the last five years, and yet they
did not do a systematic review of that literature. In quite a few cases,
recommendations are based on what’s called the Grade III inconclusive
evidence. There are three grades that they give evidence to judge its
quality – Grade I, II, and III for available evidence.
There are a number of recommendations – including the vegetarian
diet – based on what they consider to be Grade III evidence, which seems
to be problematic to me. They are not supposed to, according to their
own procedures, make recommendations based on such weak evidence.
Probably one of the more controversial parts of the article was that I
talked about what kinds of bias might have entered into the report.”
Strangely enough, committee members are not required to reveal their
conflict of interest, which in and of itself raises questions. Despite
bringing forth a number of important concerns, her article raised many
angry and defensive responses. The Center for Science in the Public
Interest (CSPI), which is closely allied with the government, got more
than 170 scientists to sign a letter asking for a retraction of the
article, based on 11 points they consider to be grievous flaws.4
“It does seem to be an effort to try to silence this article, a
kind of censorship to prevent these issues from being discussed and
debated as they should,” Teicholz says.
“The main point is that the dietary guidelines are clearly not working...The
nicest thing you can say is that they have failed to fight obesity and
diabetes. The meanest thing you could say is that they caused those
conditions. The truth has to be somewhere in that range of
possibilities...Scientists in this field ought to be curious. Why aren’t
the guidelines working? Here’s a clue: maybe they aren’t based on good
science. Take the clue and run with it—that ought to be the response to
this article.”
Processed Vegetables Oils Have Done Great Harm
Unfortunately, there are very real consequences to getting the
dietary guidelines wrong. One example of this is the vilification of
saturated fats and the encouragement to decrease fat consumption. That
left us with polyunsaturated fats, which can be healthy as we need some omega-6 fats, but not in the form of processed vegetable oils. These have likely caused more harm than the overall increase in carbohydrates.
As noted by Teicholz, the rise in heart disease in the U.S. goes in
perfect lockstep with the rise in vegetable oils in the early 1920’s and
30’s. It was an unintended consequence of getting rid of saturated
fats—a move partly orchestrated by the industry, which developed ways to
extract oils from seeds and beans.
Today we’re dealing with another, very similar fallout. Once the FDA
banned trans fats, the food industry started using interesterified fats
and traditional vegetable oils, which produce extremely toxic byproducts
when heated. One category called aldehydes are highly inflammatory, and
may promote heart disease and Alzheimer’s.
So by not going far enough, and failing to make the recommendation to switch back to lard and other healthier fats, we may simply have jumped from the proverbial frying pan into the fire.
Saturated Fat Is Still Wrongly Vilified
The 2015-2020 dietary guidelines still recommend capping saturated
fat consumption at a maximum of 10 percent of your daily calories.
Personally, I eat a whole lot more than that, and there’s evidence to
suggest some people may benefit from as much as 50 to 80 percent.
Teicholz has done serious study in this area, and she offers the
following rebuttal to those who insist saturated fat should be limited
to protect your heart health:
“Saturated fats were condemned in the 1950s because they raised
total cholesterol. When they could do better measurements, it shifted
from total cholesterol to LDL cholesterol. But neither total nor LDL
cholesterol, it turns out track very well with your heart attack risk.
In other words, you’re just as likely to get a heart attack if you have
high LDL as you have low LDL. That’s been shown in a number of clinical
trials with thousands of people.
It turns out that, according to more reliable biomarkers – HDL
cholesterol, your triglycerides, your LDL particle number, your LDL
subfraction size, more up-to-date biomarkers that have now been
developed that more reliably track with heart attacks – saturated fats
looks perfectly good, if not healthy. In fact, saturated fats are the
only food you can eat if you were to raise your HDL...
There’s also the fact that in the ‘60s and ‘70s, there were many
large clinical trials on tens of thousands of people... where they took
out saturated fats and replaced it with vegetable oils...reducing
saturated fats down to 9 percent. In all of those trials, they could not
demonstrate that reducing saturated fat reduced cardiovascular
mortality. Those trials, a huge body of evidence, have basically been
suppressed and ignored for decades.”
In the last five years, however, nearly a dozen systematic reviews
and meta-analyses have looked at that clinical trial data, concluding
that saturated fats have no adverse effect on cardiovascular mortality.
Yet the dietary guideline committee did not systematically review
this evidence, even though they’re tasked with reviewing any new
evidence that has emerged in the past five years. “They left a lot out,
and that’s why they could come to the conclusion that the evidence
against saturated fats was still strong in their view,” Teicholz says.
For the First Time, Dietary Guidelines Must Undergo Peer-Review
Interestingly, for the first time ever, Congress is getting involved.
A meeting was held in October 2015, during which members of Congress
asked USDA Secretary Tom Vilsack and Health and Human Services Secretary
Sylvia Burwell (who are jointly responsible for the dietary guidelines)
a number of questions, including: ‘Why did your experts not use the
Nutrition Evidence Library like they’re supposed to?,’ ‘Why are you
issuing recommendations on children when there’s no data on children?,’
and “Why are the guidelines still a one-size-fits-all recommendation?’
“That level of concern is much higher than it has been in recent
history, if ever, again, because the dietary guidelines haven’t worked.
Anybody can see that, so there is a high level of concern in the
Congress about it,” Teicholz says. In the end, Congress mandated the
first ever peer-review of the dietary guidelines by the National Academy
of Medicine.
They also asked members of the 2015 Dietary Guidelines expert
committee to recuse themselves from the process. It’s unclear how long
it will take to complete this review, but it will certainly be
interesting to see the results.
Silver Linings
While there are still many problems with the dietary guidelines, a
few recommendations have shifted in the right direction. For example,
for the first time ever, they now recommend limiting sugar to a maximum
of 10 percent of your total calories. They also suggest reducing refined
grains. Another first: coffee and alcohol were singled out as being
healthy in moderate amounts.
However, even though the guidelines tell you to avoid refined grains
and eat more healthy whole grains, the actual diet model distributed to
all the food assistance programs show the same amount of refined grains
as before—three to five servings of refined grains, and three to five
servings of whole grains. Why did they do that?
Teicholz theory on this is that it has to do with fortification.
Refined grains, like breakfast cereals are typically fortified, allowing
them to get specific nutrients into the food supply, because, believe
it or not, the dietary guidelines do not actually meet nutrient targets
for vitamins and minerals. And why don’t they meet nutritional
sufficiency?
“My hypothesis is because they limit saturated fats. Most the
nutrient-dense foods where those are found are organ meats, meat, dairy,
and eggs – that’s where you’ll find the nutrients. So bizarrely, that’s
why you have to recommend Americans to eat three to five servings of
refined grains every day. That’s one reason,” Teicholz says.
Why the Dietary Guidelines Are Inappropriate for Most Americans
Another positive change is the shift in focus from individual
nutrients to dietary patterns. As Teicholz says, “Nobody goes to dinner
and says, ‘Can I have 25 percent fat, please?’ You talk about food.”
Examples of food patterns include the vegetarian and the
Mediterranean style diet. On the downside, when Teicholz analyzed the
actual amount of food in these dietary patterns, the same old patterns
were found again. They all consist of about 55 percent carbohydrates, 32
to 34 percent fat, and they all recommend most of the same foods.
“The issue is that people do respond very individually to diet.
There are different nutritional needs for children. Women respond
differently from men. The elderly have different nutritional needs.
There are genetic factors that influence people’s responses. To continue
with the one-size-fits-all diet seems too foolhardy and not a good kind
of policy to have,” she says.
“There’s also the particular variation in the American population
now, which is metabolic health. If you are obese or have diabetes, that
is a sign of your intolerance to a certain kind of carbohydrates. There
needs to be included in the guidelines a recommendation for those
people, because who are those people?
Two-thirds of Americans are overweight or obese. More than half are pre-diabetic or diabetic. The guidelines are not
for those people. So you’re talking about a policy that doesn’t address
the majority of America. But there’s no big caveat that comes with the
guidelines saying, “Hey America, most of these are not for most of you.”
Basic Advice: Eat Real Food
Perhaps the broadest dietary recommendation for health is simply to eat real food.
Sure, people might eat more fat, but if it’s processed vegetables oils,
you’ll simply get sick and die prematurely. By eating real food, as
close to its natural state as possible, you’re likely to be much
healthier simply because you’ll avoid a lot of processed foods.
Science actually confirms that a wide variety of diets can be healthy
— provided they're based on real food, as unadulterated foods contain
all the nutrients your body needs, and in far more ideal ratios than
nutritional scientists can guesstimate.
Another requirement is that your diet be nutritionally sufficient and
have the basic nutrients needed for life. “I think if you say eat real food that is nutritionally sufficient,
that would be enough. That would narrow down your options,” Teicholz
says. There are some really good databases out there that can help you
determine whether or not you’re meeting your nutritional needs.
Beware that even this strategy has its shortcomings though. As noted
by Teicholz: “The subtle twist is that nutrients are not all equally
bioavailable from all foods. You need to eat, for example, fat-soluble
vitamins with fats ... If you don’t have the vitamins, you can’t absorb
the minerals.
So it’s more complicated than just simply tallying it up. But it’s a good start.” It can be especially useful for determining the ratios
of nutrients in your diet, such as the percentage of protein,
carbohydrates, and fat, or the ratio of saturated versus polyunsaturated
fat.
For more guidance on what makes for a healthy diet, I recommend reading through my optimized nutrition plan. You may also print out my version of the food pyramid.
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