[R-G] [BillTottenWeblog] Unhappy Meals

[Bill Totten]

by Michael Pollan

The New York Times (January 28 2007)


Eat food. Not too much. Mostly plants.

That, more or less, is the short answer to the supposedly incredibly
complicated and confusing question of what we humans should eat in order
to be maximally healthy. I hate to give away the game right here at the
beginning of a long essay, and I confess that I'm tempted to complicate
matters in the interest of keeping things going for a few thousand more
words. I'll try to resist but will go ahead and add a couple more
details to flesh out the advice. Like: A little meat won't kill you,
though it's better approached as a side dish than as a main. And you're
much better off eating whole fresh foods than processed food products.
That's what I mean by the recommendation to eat "food". Once, food was
all you could eat, but today there are lots of other edible foodlike
substances in the supermarket. These novel products of food science
often come in packages festooned with health claims, which brings me to
a related rule of thumb: if you're concerned about your health, you
should probably avoid food products that make health claims. Why?
Because a health claim on a food product is a good indication that it's
not really food, and food is what you want to eat.

Uh-oh. Things are suddenly sounding a little more complicated, aren't
they? Sorry. But that's how it goes as soon as you try to get to the
bottom of the whole vexing question of food and health. Before long, a
dense cloud bank of confusion moves in. Sooner or later, everything
solid you thought you knew about the links between diet and health gets
blown away in the gust of the latest study.

Last winter came the news that a low-fat diet, long believed to protect
against breast cancer, may do no such thing - this from the monumental,
federally financed Women's Health Initiative, which has also found no
link between a low-fat diet and rates of coronary disease. The year
before we learned that dietary fiber might not, as we had been
confidently told, help prevent colon cancer. Just last fall two
prestigious studies on omega-3 fats published at the same time presented
us with strikingly different conclusions. While the Institute of
Medicine stated that "it is uncertain how much these omega-3s contribute
to improving health" (and they might do the opposite if you get them
from mercury-contaminated fish), a Harvard study declared that simply by
eating a couple of servings of fish each week (or by downing enough fish
oil), you could cut your risk of dying from a heart attack by more than
a third - a stunningly hopeful piece of news. It's no wonder that
omega-3 fatty acids are poised to become the oat bran of 2007, as food
scientists micro-encapsulate fish oil and algae oil and blast them into
such formerly all-terrestrial foods as bread and tortillas, milk and
yogurt and cheese, all of which will soon, you can be sure, sprout fishy
new health claims. (Remember the rule?)

By now you're probably registering the cognitive dissonance of the
supermarket shopper or science-section reader, as well as some nostalgia
for the simplicity and solidity of the first few sentences of this
essay. Which I'm still prepared to defend against the shifting winds of
nutritional science and food-industry marketing. But before I do that,
it might be useful to figure out how we arrived at our present state of
nutritional confusion and anxiety.

The story of how the most basic questions about what to eat ever got so
complicated reveals a great deal about the institutional imperatives of
the food industry, nutritional science and - ahem - journalism, three
parties that stand to gain much from widespread confusion surrounding
what is, after all, the most elemental question an omnivore confronts.
Humans deciding what to eat without expert help - something they have
been doing with notable success since coming down out of the trees - is
seriously unprofitable if you're a food company, distinctly risky if
you're a nutritionist and just plain boring if you're a newspaper editor
or journalist. (Or, for that matter, an eater. Who wants to hear, yet
again, "Eat more fruits and vegetables"?) And so, like a large gray fog,
a great Conspiracy of Confusion has gathered around the simplest
questions of nutrition - much to the advantage of everybody involved.
Except perhaps the ostensible beneficiary of all this nutritional
expertise and advice: us, and our health and happiness as eaters.

FROM FOODS TO NUTRIENTS

It was in the 1980s that food began disappearing from the American
supermarket, gradually to be replaced by "nutrients", which are not the
same thing. Where once the familiar names of recognizable comestibles -
things like eggs or breakfast cereal or cookies - claimed pride of place
on the brightly colored packages crowding the aisles, now new terms like
"fiber" and "cholesterol" and "saturated fat" rose to large-type
prominence. More important than mere foods, the presence or absence of
these invisible substances was now generally believed to confer health
benefits on their eaters. Foods by comparison were coarse, old-fashioned
and decidedly unscientific things - who could say what was in them,
really? But nutrients - those chemical compounds and minerals in foods
that nutritionists have deemed important to health - gleamed with the
promise of scientific certainty; eat more of the right ones, fewer of
the wrong, and you would live longer and avoid chronic diseases.

Nutrients themselves had been around, as a concept, since the early 19th
century, when the English doctor and chemist William Prout identified
what came to be called the "macronutrients": protein, fat and
carbohydrates. It was thought that that was pretty much all there was
going on in food, until doctors noticed that an adequate supply of the
big three did not necessarily keep people nourished. At the end of the
19th century, British doctors were puzzled by the fact that Chinese
laborers in the Malay states were dying of a disease called beriberi,
which didn't seem to afflict Tamils or native Malays. The mystery was
solved when someone pointed out that the Chinese ate "polished", or
white, rice, while the others ate rice that hadn't been mechanically
milled. A few years later, Casimir Funk, a Polish chemist, discovered
the "essential nutrient" in rice husks that protected against beriberi
and called it a "vitamine", the first micronutrient. Vitamins brought a
kind of glamour to the science of nutrition, and though certain sectors
of the population began to eat by its expert lights, it really wasn't
until late in the 20th century that nutrients managed to push food aside
in the popular imagination of what it means to eat.

No single event marked the shift from eating food to eating nutrients,
though in retrospect a little-noticed political dust-up in Washington in
1977 seems to have helped propel American food culture down this dimly
lighted path. Responding to an alarming increase in chronic diseases
linked to diet - including heart disease, cancer and diabetes - a Senate
Select Committee on Nutrition, headed by George McGovern, held hearings
on the problem and prepared what by all rights should have been an
uncontroversial document called "Dietary Goals for the United States".
The committee learned that while rates of coronary heart disease had
soared in America since World War II, other cultures that consumed
traditional diets based largely on plants had strikingly low rates of
chronic disease. Epidemiologists also had observed that in America
during the war years, when meat and dairy products were strictly
rationed, the rate of heart disease temporarily plummeted.

Naively putting two and two together, the committee drafted a
straightforward set of dietary guidelines calling on Americans to cut
down on red meat and dairy products. Within weeks a firestorm, emanating
from the red-meat and dairy industries, engulfed the committee, and
Senator McGovern (who had a great many cattle ranchers among his South
Dakota constituents) was forced to beat a retreat. The committee's
recommendations were hastily rewritten. Plain talk about food - the
committee had advised Americans to actually "reduce consumption of meat"
- was replaced by artful compromise: "Choose meats, poultry and fish
that will reduce saturated-fat intake".

A subtle change in emphasis, you might say, but a world of difference
just the same. First, the stark message to "eat less" of a particular
food has been deep-sixed; don't look for it ever again in any official
US dietary pronouncement. Second, notice how distinctions between
entities as different as fish and beef and chicken have collapsed; those
three venerable foods, each representing an entirely different taxonomic
class, are now lumped together as delivery systems for a single
nutrient. Notice too how the new language exonerates the foods
themselves; now the culprit is an obscure, invisible, tasteless - and
politically unconnected - substance that may or may not lurk in them
called "saturated fat".

The linguistic capitulation did nothing to rescue McGovern from his
blunder; the very next election, in 1980, the beef lobby helped
rusticate the three-term senator, sending an unmistakable warning to
anyone who would challenge the American diet, and in particular the big
chunk of animal protein sitting in the middle of its plate. Henceforth,
government dietary guidelines would shun plain talk about whole foods,
each of which has its trade association on Capitol Hill, and would
instead arrive clothed in scientific euphemism and speaking of
nutrients, entities that few Americans really understood but that lack
powerful lobbies in Washington. This was precisely the tack taken by the
National Academy of Sciences when it issued its landmark report on diet
and cancer in 1982. Organized nutrient by nutrient in a way guaranteed
to offend no food group, it codified the official new dietary language.
Industry and media followed suit, and terms like polyunsaturated,
cholesterol, monounsaturated, carbohydrate, fiber, polyphenols, amino
acids and carotenes soon colonized much of the cultural space previously
occupied by the tangible substance formerly known as food. The Age of
Nutritionism had arrived.

THE RISE OF NUTRITIONISM

The first thing to understand about nutritionism - I first encountered
the term in the work of an Australian sociologist of science named
Gyorgy Scrinis - is that it is not quite the same as nutrition. As the
"ism" suggests, it is not a scientific subject but an ideology.
Ideologies are ways of organizing large swaths of life and experience
under a set of shared but unexamined assumptions. This quality makes an
ideology particularly hard to see, at least while it's exerting its hold
on your culture. A reigning ideology is a little like the weather, all
pervasive and virtually inescapable. Still, we can try.

In the case of nutritionism, the widely shared but unexamined assumption
is that the key to understanding food is indeed the nutrient. From this
basic premise flow several others. Since nutrients, as compared with
foods, are invisible and therefore slightly mysterious, it falls to the
scientists (and to the journalists through whom the scientists speak) to
explain the hidden reality of foods to us. To enter a world in which you
dine on unseen nutrients, you need lots of expert help.

But expert help to do what, exactly? This brings us to another
unexamined assumption: that the whole point of eating is to maintain and
promote bodily health. Hippocrates's famous injunction to "let food be
thy medicine" is ritually invoked to support this notion. I'll leave the
premise alone for now, except to point out that it is not shared by all
cultures and that the experience of these other cultures suggests that,
paradoxically, viewing food as being about things other than bodily
health - like pleasure, say, or socializing - makes people no less
healthy; indeed, there's some reason to believe that it may make them
more healthy. This is what we usually have in mind when we speak of the
"French paradox" - the fact that a population that eats all sorts of
unhealthful nutrients is in many ways healthier than we Americans are.
So there is at least a question as to whether nutritionism is actually
any good for you.

Another potentially serious weakness of nutritionist ideology is that it
has trouble discerning qualitative distinctions between foods. So fish,
beef and chicken through the nutritionists' lens become mere delivery
systems for varying quantities of fats and proteins and whatever other
nutrients are on their scope. Similarly, any qualitative distinctions
between processed foods and whole foods disappear when your focus is on
quantifying the nutrients they contain (or, more precisely, the known
nutrients).

This is a great boon for manufacturers of processed food, and it helps
explain why they have been so happy to get with the nutritionism
program. In the years following McGovern's capitulation and the 1982
National Academy report, the food industry set about re-engineering
thousands of popular food products to contain more of the nutrients that
science and government had deemed the good ones and less of the bad, and
by the late 1980s a golden era of food science was upon us. The Year of
Eating Oat Bran - also known as 1988 - served as a kind of coming-out
party for the food scientists, who succeeded in getting the material
into nearly every processed food sold in America. Oat bran's moment on
the dietary stage didn't last long, but the pattern had been
established, and every few years since then a new oat bran has taken its
turn under the marketing lights. (Here comes omega-3!)

By comparison, the typical real food has more trouble competing under
the rules of nutritionism, if only because something like a banana or an
avocado can't easily change its nutritional stripes (though rest assured
the genetic engineers are hard at work on the problem). So far, at
least, you can't put oat bran in a banana. So depending on the reigning
nutritional orthodoxy, the avocado might be either a high-fat food to be
avoided (Old Think) or a food high in monounsaturated fat to be embraced
(New Think). The fate of each whole food rises and falls with every
change in the nutritional weather, while the processed foods are simply
reformulated. That's why when the Atkins mania hit the food industry,
bread and pasta were given a quick redesign (dialing back the carbs;
boosting the protein), while the poor unreconstructed potatoes and
carrots were left out in the cold.

Of course it's also a lot easier to slap a health claim on a box of
sugary cereal than on a potato or carrot, with the perverse result that
the most healthful foods in the supermarket sit there quietly in the
produce section, silent as stroke victims, while a few aisles over, the
Cocoa Puffs and Lucky Charms are screaming about their newfound
whole-grain goodness.

EAT RIGHT, GET FATTER

So nutritionism is good for business. But is it good for us? You might
think that a national fixation on nutrients would lead to measurable
improvements in the public health. But for that to happen, the
underlying nutritional science, as well as the policy recommendations
(and the journalism) based on that science, would have to be sound. This
has seldom been the case.

Consider what happened immediately after the 1977 "Dietary Goals" -
McGovern's masterpiece of politico-nutritionist compromise. In the wake
of the panel's recommendation that we cut down on saturated fat, a
recommendation seconded by the 1982 National Academy report on cancer,
Americans did indeed change their diets, endeavoring for a
quarter-century to do what they had been told. Well, kind of. The
industrial food supply was promptly reformulated to reflect the official
advice, giving us low-fat pork, low-fat Snackwell's and all the low-fat
pasta and high-fructose (yet low-fat!) corn syrup we could consume.
Which turned out to be quite a lot. Oddly, America got really fat on its
new low-fat diet - indeed, many date the current obesity and diabetes
epidemic to the late 1970s, when Americans began binging on
carbohydrates, ostensibly as a way to avoid the evils of fat.

This story has been told before, notably in these pages ("What if It's
All Been a Big Fat Lie?" by Gary Taubes, July 7 2002), but it's a little
more complicated than the official version suggests. In that version,
which inspired the most recent Atkins craze, we were told that America
got fat when, responding to bad scientific advice, it shifted its diet
from fats to carbs, suggesting that a re-evaluation of the two nutrients
is in order: fat doesn't make you fat; carbs do. (Why this should have
come as news is a mystery: as long as people have been raising animals
for food, they have fattened them on carbs.)

But there are a couple of problems with this revisionist picture. First,
while it is true that Americans post-1977 did begin binging on carbs,
and that fat as a percentage of total calories in the American diet
declined, we never did in fact cut down on our consumption of fat. Meat
consumption actually climbed. We just heaped a bunch more carbs onto our
plates, obscuring perhaps, but not replacing, the expanding chunk of
animal protein squatting in the center.

How did that happen? I would submit that the ideology of nutritionism
deserves as much of the blame as the carbohydrates themselves do - that
and human nature. By framing dietary advice in terms of good and bad
nutrients, and by burying the recommendation that we should eat less of
any particular food, it was easy for the take-home message of the 1977
and 1982 dietary guidelines to be simplified as follows: Eat more
low-fat foods. And that is what we did. We're always happy to receive a
dispensation to eat more of something (with the possible exception of
oat bran), and one of the things nutritionism reliably gives us is some
such dispensation: low-fat cookies then, low-carb beer now. It's hard to
imagine the low-fat craze taking off as it did if McGovern's original
food-based recommendations had stood: eat fewer meat and dairy products.
For how do you get from that stark counsel to the idea that another case
of Snackwell's is just what the doctor ordered?

BAD SCIENCE

But if nutritionism leads to a kind of false consciousness in the mind
of the eater, the ideology can just as easily mislead the scientist.
Most nutritional science involves studying one nutrient at a time, an
approach that even nutritionists who do it will tell you is deeply
flawed. "The problem with nutrient-by-nutrient nutrition science",
points out Marion Nestle, the New York University nutritionist, "is that
it takes the nutrient out of the context of food, the food out of the
context of diet and the diet out of the context of lifestyle".

If nutritional scientists know this, why do they do it anyway? Because a
nutrient bias is built into the way science is done: scientists need
individual variables they can isolate. Yet even the simplest food is a
hopelessly complex thing to study, a virtual wilderness of chemical
compounds, many of which exist in complex and dynamic relation to one
another, and all of which together are in the process of changing from
one state to another. So if you're a nutritional scientist, you do the
only thing you can do, given the tools at your disposal: break the thing
down into its component parts and study those one by one, even if that
means ignoring complex interactions and contexts, as well as the fact
that the whole may be more than, or just different from, the sum of its
parts. This is what we mean by reductionist science.

Scientific reductionism is an undeniably powerful tool, but it can
mislead us too, especially when applied to something as complex as, on
the one side, a food, and on the other, a human eater. It encourages us
to take a mechanistic view of that transaction: put in this nutrient;
get out that physiological result. Yet people differ in important ways.
Some populations can metabolize sugars better than others; depending on
your evolutionary heritage, you may or may not be able to digest the
lactose in milk. The specific ecology of your intestines helps determine
how efficiently you digest what you eat, so that the same input of 100
calories may yield more or less energy depending on the proportion of
Firmicutes and Bacteroidetes living in your gut. There is nothing very
machinelike about the human eater, and so to think of food as simply
fuel is wrong.

Also, people don't eat nutrients, they eat foods, and foods can behave
very differently than the nutrients they contain. Researchers have long
believed, based on epidemiological comparisons of different populations,
that a diet high in fruits and vegetables confers some protection
against cancer. So naturally they ask, What nutrients in those plant
foods are responsible for that effect? One hypothesis is that the
antioxidants in fresh produce - compounds like beta carotene, lycopene,
vitamin E, et cetera - are the X factor. It makes good sense: these
molecules (which plants produce to protect themselves from the highly
reactive oxygen atoms produced in photosynthesis) vanquish the free
radicals in our bodies, which can damage DNA and initiate cancers. At
least that's how it seems to work in the test tube. Yet as soon as you
remove these useful molecules from the context of the whole foods
they're found in, as we've done in creating antioxidant supplements,
they don't work at all. Indeed, in the case of beta carotene ingested as
a supplement, scientists have discovered that it actually increases the
risk of certain cancers. Big oops.

What's going on here? We don't know. It could be the vagaries of human
digestion. Maybe the fiber (or some other component) in a carrot
protects the antioxidant molecules from destruction by stomach acids
early in the digestive process. Or it could be that we isolated the
wrong antioxidant. Beta is just one of a whole slew of carotenes found
in common vegetables; maybe we focused on the wrong one. Or maybe beta
carotene works as an antioxidant only in concert with some other plant
chemical or process; under other circumstances, it may behave as a
pro-oxidant.

Indeed, to look at the chemical composition of any common food plant is
to realize just how much complexity lurks within it. Here's a list of
just the antioxidants that have been identified in garden-variety thyme:

4-Terpineol, alanine, anethole, apigenin, ascorbic acid, beta carotene,
caffeic acid, camphene, carvacrol, chlorogenic acid, chrysoeriol,
eriodictyol, eugenol, ferulic acid, gallic acid, gamma-terpinene
isochlorogenic acid, isoeugenol, isothymonin, kaempferol, labiatic acid,
lauric acid, linalyl acetate, luteolin, methionine, myrcene, myristic
acid, naringenin, oleanolic acid, p-coumoric acid, p-hydroxy-benzoic
acid, palmitic acid, rosmarinic acid, selenium, tannin, thymol,
tryptophan, ursolic acid, vanillic acid.

This is what you're ingesting when you eat food flavored with thyme.
Some of these chemicals are broken down by your digestion, but others
are going on to do undetermined things to your body: turning some gene's
expression on or off, perhaps, or heading off a free radical before it
disturbs a strand of DNA deep in some cell. It would be great to know
how this all works, but in the meantime we can enjoy thyme in the
knowledge that it probably doesn't do any harm (since people have been
eating it forever) and that it may actually do some good (since people
have been eating it forever) and that even if it does nothing, we like
the way it tastes.

It's also important to remind ourselves that what reductive science can
manage to perceive well enough to isolate and study is subject to
change, and that we have a tendency to assume that what we can see is
all there is to see. When William Prout isolated the big three
macronutrients, scientists figured they now understood food and what the
body needs from it; when the vitamins were isolated a few decades later,
scientists thought, okay, now we really understand food and what the
body needs to be healthy; today it's the polyphenols and carotenoids
that seem all-important. But who knows what the hell else is going on
deep in the soul of a carrot?

The good news is that, to the carrot eater, it doesn't matter. That's
the great thing about eating food as compared with nutrients: you don't
need to fathom a carrot's complexity to reap its benefits.

The case of the antioxidants points up the dangers in taking a nutrient
out of the context of food; as Nestle suggests, scientists make a
second, related error when they study the food out of the context of the
diet. We don't eat just one thing, and when we are eating any one thing,
we're not eating another. We also eat foods in combinations and in
orders that can affect how they're absorbed. Drink coffee with your
steak, and your body won't be able to fully absorb the iron in the meat.
The trace of limestone in the corn tortilla unlocks essential amino
acids in the corn that would otherwise remain unavailable. Some of those
compounds in that sprig of thyme may well affect my digestion of the
dish I add it to, helping to break down one compound or possibly
stimulate production of an enzyme to detoxify another. We have barely
begun to understand the relationships among foods in a cuisine.

But we do understand some of the simplest relationships, like the
zero-sum relationship: that if you eat a lot of meat you're probably not
eating a lot of vegetables. This simple fact may explain why populations
that eat diets high in meat have higher rates of coronary heart disease
and cancer than those that don't. Yet nutritionism encourages us to look
elsewhere for the explanation: deep within the meat itself, to the
culpable nutrient, which scientists have long assumed to be the
saturated fat. So they are baffled when large-population studies, like
the Women's Health Initiative, fail to find that reducing fat intake
significantly reduces the incidence of heart disease or cancer.

Of course thanks to the low-fat fad (inspired by the very same
reductionist fat hypothesis), it is entirely possible to reduce your
intake of saturated fat without significantly reducing your consumption
of animal protein: just drink the low-fat milk and order the skinless
chicken breast or the turkey bacon. So maybe the culprit nutrient in
meat and dairy is the animal protein itself, as some researchers now
hypothesize. The Cornell nutritionist T Colin Campbell argues as much in
his recent book, The China Study (2005). Or, as the Harvard
epidemiologist Walter C Willett suggests, it could be the steroid
hormones typically present in the milk and meat; these hormones (which
occur naturally in meat and milk but are often augmented in industrial
production) are known to promote certain cancers.

But people worried about their health needn't wait for scientists to
settle this question before deciding that it might be wise to eat more
plants and less meat. This is of course precisely what the McGovern
committee was trying to tell us.

Nestle also cautions against taking the diet out of the context of the
lifestyle. The Mediterranean diet is widely believed to be one of the
most healthful ways to eat, yet much of what we know about it is based
on studies of people living on the island of Crete in the 1950s, who in
many respects lived lives very different from our own. Yes, they ate
lots of olive oil and little meat. But they also did more physical
labor. They fasted regularly. They ate a lot of wild greens - weeds.
And, perhaps most important, they consumed far fewer total calories than
we do. Similarly, much of what we know about the health benefits of a
vegetarian diet is based on studies of Seventh Day Adventists, who muddy
the nutritional picture by drinking absolutely no alcohol and never
smoking. These extraneous but unavoidable factors are called, aptly,
"confounders". One last example: People who take supplements are
healthier than the population at large, but their health probably has
nothing whatsoever to do with the supplements they take - which recent
studies have suggested are worthless. Supplement-takers are
better-educated, more-affluent people who, almost by definition, take a
greater-than-normal interest in personal health - confounding factors
that probably account for their superior health.

But if confounding factors of lifestyle bedevil comparative studies of
different populations, the supposedly more rigorous "prospective"
studies of large American populations suffer from their own arguably
even more disabling flaws. In these studies - of which the Women's
Health Initiative is the best known - a large population is divided into
two groups. The intervention group changes its diet in some prescribed
manner, while the control group does not. The two groups are then
tracked over many years to learn whether the intervention affects
relative rates of chronic disease.

When it comes to studying nutrition, this sort of extensive, long-term
clinical trial is supposed to be the gold standard. It certainly sounds
sound. In the case of the Women's Health Initiative, sponsored by the
National Institutes of Health, the eating habits and health outcomes of
nearly 49,000 women (ages 50 to 79 at the beginning of the study) were
tracked for eight years. One group of the women were told to reduce
their consumption of fat to twenty percent of total calories. The
results were announced early last year, producing front-page headlines
of which the one in this newspaper was typical: "Low-Fat Diet Does Not
Cut Health Risks, Study Finds". And the cloud of nutritional confusion
over the country darkened.

But even a cursory analysis of the study's methods makes you wonder why
anyone would take such a finding seriously, let alone order a Quarter
Pounder With Cheese to celebrate it, as many newspaper readers no doubt
promptly went out and did. Even the beginner student of nutritionism
will immediately spot several flaws: the focus was on "fat", rather than
on any particular food, like meat or dairy. So women could comply simply
by switching to lower-fat animal products. Also, no distinctions were
made between types of fat: women getting their allowable portion of fat
from olive oil or fish were lumped together with woman getting their fat
from low-fat cheese or chicken breasts or margarine. Why? Because when
the study was designed 16 years ago, the whole notion of "good fats" was
not yet on the scientific scope. Scientists study what scientists can see.

But perhaps the biggest flaw in this study, and other studies like it,
is that we have no idea what these women were really eating because,
like most people when asked about their diet, they lied about it. How do
we know this? Deduction. Consider: When the study began, the average
participant weighed in at 170 pounds and claimed to be eating 1,800
calories a day. It would take an unusual metabolism to maintain that
weight on so little food. And it would take an even freakier metabolism
to drop only one or two pounds after getting down to a diet of 1,400 to
1,500 calories a day - as the women on the "low-fat" regimen claimed to
have done. Sorry, ladies, but I just don't buy it.

In fact, nobody buys it. Even the scientists who conduct this sort of
research conduct it in the knowledge that people lie about their food
intake all the time. They even have scientific figures for the magnitude
of the lie. Dietary trials like the Women's Health Initiative rely on
"food-frequency questionnaires", and studies suggest that people on
average eat between a fifth and a third more than they claim to on the
questionnaires. How do the researchers know that? By comparing what
people report on questionnaires with interviews about their dietary
intake over the previous 24 hours, thought to be somewhat more reliable.
In fact, the magnitude of the lie could be much greater, judging by the
huge disparity between the total number of food calories produced every
day for each American (3,900 calories) and the average number of those
calories Americans own up to chomping: 2,000. (Waste accounts for some
of the disparity, but nowhere near all of it.) All we really know about
how much people actually eat is that the real number lies somewhere
between those two figures.

To try to fill out the food-frequency questionnaire used by the Women's
Health Initiative, as I recently did, is to realize just how shaky the
data on which such trials rely really are. The survey, which took about
45 minutes to complete, started off with some relatively easy questions:
"Did you eat chicken or turkey during the last three months?" Having
answered yes, I was then asked, "When you ate chicken or turkey, how
often did you eat the skin?" But the survey soon became harder, as when
it asked me to think back over the past three months to recall whether
when I ate okra, squash or yams, they were fried, and if so, were they
fried in stick margarine, tub margarine, butter, "shortening" (in which
category they inexplicably lump together hydrogenated vegetable oil and
lard), olive or canola oil or nonstick spray? I honestly didn't
remember, and in the case of any okra eaten in a restaurant, even a
hypnotist could not get out of me what sort of fat it was fried in. In
the meat section, the portion sizes specified haven't been seen in
America since the Hoover administration. If a four-ounce portion of
steak is considered "medium", was I really going to admit that the steak
I enjoyed on an unrecallable number of occasions during the past three
months was probably the equivalent of two or three (or, in the case of a
steakhouse steak, no less than four) of these portions? I think not. In
fact, most of the "medium serving sizes" to which I was asked to compare
my own consumption made me feel piggish enough to want to shave a few
ounces here, a few there. (I mean, I wasn't under oath or anything, was I?)

This is the sort of data on which the largest questions of diet and
health are being decided in America today.

THE ELEPHANT IN THE ROOM

In the end, the biggest, most ambitious and widely reported studies of
diet and health leave more or less undisturbed the main features of the
Western diet: lots of meat and processed foods, lots of added fat and
sugar, lots of everything - except fruits, vegetables and whole grains.
In keeping with the nutritionism paradigm and the limits of reductionist
science, the researchers fiddle with single nutrients as best they can,
but the populations they recruit and study are typical American eaters
doing what typical American eaters do: trying to eat a little less of
this nutrient, a little more of that, depending on the latest thinking.
(One problem with the control groups in these studies is that they too
are exposed to nutritional fads in the culture, so over time their
eating habits come to more closely resemble the habits of the
intervention group.) It should not surprise us that the findings of such
research would be so equivocal and confusing.

But what about the elephant in the room - the Western diet? It might be
useful, in the midst of our deepening confusion about nutrition, to
review what we do know about diet and health. What we know is that
people who eat the way we do in America today suffer much higher rates
of cancer, heart disease, diabetes and obesity than people eating more
traditional diets. (Four of the 10 leading killers in America are linked
to diet.) Further, we know that simply by moving to America, people from
nations with low rates of these "diseases of affluence" will quickly
acquire them. Nutritionism by and large takes the Western diet as a
given, seeking to moderate its most deleterious effects by isolating the
bad nutrients in it - things like fat, sugar, salt - and encouraging the
public and the food industry to limit them. But after several decades of
nutrient-based health advice, rates of cancer and heart disease in the
US have declined only slightly (mortality from heart disease is down
since the '50s, but this is mainly because of improved treatment), and
rates of obesity and diabetes have soared.

No one likes to admit that his or her best efforts at understanding and
solving a problem have actually made the problem worse, but that's
exactly what has happened in the case of nutritionism. Scientists
operating with the best of intentions, using the best tools at their
disposal, have taught us to look at food in a way that has diminished
our pleasure in eating it while doing little or nothing to improve our
health. Perhaps what we need now is a broader, less reductive view of
what food is, one that is at once more ecological and cultural. What
would happen, for example, if we were to start thinking about food as
less of a thing and more of a relationship?

In nature, that is of course precisely what eating has always been:
relationships among species in what we call food chains, or webs, that
reach all the way down to the soil. Species co-evolve with the other
species they eat, and very often a relationship of interdependence
develops: I'll feed you if you spread around my genes. A gradual process
of mutual adaptation transforms something like an apple or a squash into
a nutritious and tasty food for a hungry animal. Over time and through
trial and error, the plant becomes tastier (and often more conspicuous)
in order to gratify the animal's needs and desires, while the animal
gradually acquires whatever digestive tools (enzymes, etc.) are needed
to make optimal use of the plant. Similarly, cow's milk did not start
out as a nutritious food for humans; in fact, it made them sick until
humans who lived around cows evolved the ability to digest lactose as
adults. This development proved much to the advantage of both the milk
drinkers and the cows.

"Health" is, among other things, the byproduct of being involved in
these sorts of relationships in a food chain - involved in a great many
of them, in the case of an omnivorous creature like us. Further, when
the health of one link of the food chain is disturbed, it can affect all
the creatures in it. When the soil is sick or in some way deficient, so
will be the grasses that grow in that soil and the cattle that eat the
grasses and the people who drink the milk. Or, as the English agronomist
Sir Albert Howard put it in 1945 in "The Soil and Health" (a founding
text of organic agriculture), we would do well to regard "the whole
problem of health in soil, plant, animal and man as one great subject".
Our personal health is inextricably bound up with the health of the
entire food web.

In many cases, long familiarity between foods and their eaters leads to
elaborate systems of communications up and down the food chain, so that
a creature's senses come to recognize foods as suitable by taste and
smell and color, and our bodies learn what to do with these foods after
they pass the test of the senses, producing in anticipation the
chemicals necessary to break them down. Health depends on knowing how to
read these biological signals: this smells spoiled; this looks ripe;
that's one good-looking cow. This is easier to do when a creature has
long experience of a food, and much harder when a food has been designed
expressly to deceive its senses - with artificial flavors, say, or
synthetic sweeteners.

Note that these ecological relationships are between eaters and whole
foods, not nutrients. Even though the foods in question eventually get
broken down in our bodies into simple nutrients, as corn is reduced to
simple sugars, the qualities of the whole food are not unimportant -
they govern such things as the speed at which the sugars will be
released and absorbed, which we're coming to see as critical to insulin
metabolism. Put another way, our bodies have a longstanding and
sustainable relationship to corn that we do not have to high-fructose
corn syrup. Such a relationship with corn syrup might develop someday
(as people evolve superhuman insulin systems to cope with regular floods
of fructose and glucose), but for now the relationship leads to ill
health because our bodies don't know how to handle these biological
novelties. In much the same way, human bodies that can cope with chewing
coca leaves - a longstanding relationship between native people and the
coca plant in South America - cannot cope with cocaine or crack, even
though the same "active ingredients" are present in all three.
Reductionism as a way of understanding food or drugs may be harmless,
even necessary, but reductionism in practice can lead to problems.

Looking at eating through this ecological lens opens a whole new
perspective on exactly what the Western diet is: a radical and rapid
change not just in our foodstuffs over the course of the 20th century
but also in our food relationships, all the way from the soil to the
meal. The ideology of nutritionism is itself part of that change. To get
a firmer grip on the nature of those changes is to begin to know how we
might make our relationships to food healthier. These changes have been
numerous and far-reaching, but consider as a start these four
large-scale ones: