What if It's All Been a Big Fat Lie?
By GARY
TAUBES
 f
the members of the American medical establishment were to have a
collective find-yourself-standing-naked-in-Times-Square-type
nightmare, this might be it. They spend 30 years ridiculing Robert
Atkins, author of the phenomenally-best-selling ''Dr. Atkins' Diet
Revolution'' and ''Dr. Atkins' New Diet Revolution,'' accusing the
Manhattan doctor of quackery and fraud, only to discover that the
unrepentant Atkins was right all along. Or maybe it's this: they
find that their very own dietary recommendations -- eat less fat and
more carbohydrates -- are the cause of the rampaging epidemic of
obesity in America. Or, just possibly this: they find out both of
the above are true.
When Atkins first published his ''Diet Revolution'' in 1972,
Americans were just coming to terms with the proposition that fat --
particularly the saturated fat of meat and dairy products -- was the
primary nutritional evil in the American diet. Atkins managed to
sell millions of copies of a book promising that we would lose
weight eating steak, eggs and butter to our heart's desire, because
it was the carbohydrates, the pasta, rice, bagels and sugar, that
caused obesity and even heart disease. Fat, he said, was harmless.
Atkins allowed his readers to eat ''truly luxurious foods without
limit,'' as he put it, ''lobster with butter sauce, steak with
bearnaise sauce . . . bacon cheeseburgers,'' but allowed no
starches or refined carbohydrates, which means no sugars or anything
made from flour. Atkins banned even fruit juices, and permitted only
a modicum of vegetables, although the latter were negotiable as the
diet progressed.
Atkins was by no means the first to get rich pushing a high-fat
diet that restricted carbohydrates, but he popularized it to an
extent that the American Medical Association considered it a
potential threat to our health. The A.M.A. attacked Atkins's diet as
a ''bizarre regimen'' that advocated ''an unlimited intake of
saturated fats and cholesterol-rich foods,'' and Atkins even had to
defend his diet in Congressional hearings.
Thirty years later, America has become weirdly polarized on the
subject of weight. On the one hand, we've been told with almost
religious certainty by everyone from the surgeon general on down,
and we have come to believe with almost religious certainty, that
obesity is caused by the excessive consumption of fat, and that if
we eat less fat we will lose weight and live longer. On the other,
we have the ever-resilient message of Atkins and decades' worth of
best-selling diet books, including ''The Zone,'' ''Sugar Busters''
and ''Protein Power'' to name a few. All push some variation of what
scientists would call the alternative hypothesis: it's not the fat
that makes us fat, but the carbohydrates, and if we eat less
carbohydrates we will lose weight and live longer.
The perversity of this alternative hypothesis is that it
identifies the cause of obesity as precisely those refined
carbohydrates at the base of the famous Food Guide Pyramid -- the
pasta, rice and bread -- that we are told should be the staple of
our healthy low-fat diet, and then on the sugar or corn syrup in the
soft drinks, fruit juices and sports drinks that we have taken to
consuming in quantity if for no other reason than that they are fat
free and so appear intrinsically healthy. While the
low-fat-is-good-health dogma represents reality as we have come to
know it, and the government has spent hundreds of millions of
dollars in research trying to prove its worth, the low-carbohydrate
message has been relegated to the realm of unscientific fantasy.
Over the past five years, however, there has been a subtle shift
in the scientific consensus. It used to be that even considering the
possibility of the alternative hypothesis, let alone researching it,
was tantamount to quackery by association. Now a small but growing
minority of establishment researchers have come to take seriously
what the low-carb-diet doctors have been saying all along. Walter
Willett, chairman of the department of nutrition at the Harvard
School of Public Health, may be the most visible proponent of
testing this heretic hypothesis. Willett is the de facto spokesman
of the longest-running, most comprehensive diet and health studies
ever performed, which have already cost upward of $100 million and
include data on nearly 300,000 individuals. Those data, says
Willett, clearly contradict the low-fat-is-good-health message ''and
the idea that all fat is bad for you; the exclusive focus on adverse
effects of fat may have contributed to the obesity epidemic.''
These researchers point out that there are plenty of reasons to
suggest that the low-fat-is-good-health hypothesis has now
effectively failed the test of time. In particular, that we are in
the midst of an obesity epidemic that started around the early
1980's, and that this was coincident with the rise of the low-fat
dogma. (Type 2 diabetes, the most common form of the disease, also
rose significantly through this period.) They say that low-fat
weight-loss diets have proved in clinical trials and real life to be
dismal failures, and that on top of it all, the percentage of fat in
the American diet has been decreasing for two decades. Our
cholesterol levels have been declining, and we have been smoking
less, and yet the incidence of heart disease has not declined as
would be expected. ''That is very disconcerting,'' Willett says.
''It suggests that something else bad is happening.''
The science behind the alternative hypothesis can be called
Endocrinology 101, which is how it's referred to by David Ludwig, a
researcher at Harvard Medical School who runs the pediatric obesity
clinic at Children's Hospital Boston, and who prescribes his own
version of a carbohydrate-restricted diet to his patients.
Endocrinology 101 requires an understanding of how carbohydrates
affect insulin and blood sugar and in turn fat metabolism and
appetite. This is basic endocrinology, Ludwig says, which is the
study of hormones, and it is still considered radical because the
low-fat dietary wisdom emerged in the 1960's from researchers almost
exclusively concerned with the effect of fat on cholesterol and
heart disease. At the time, Endocrinology 101 was still
underdeveloped, and so it was ignored. Now that this science is
becoming clear, it has to fight a quarter century of anti-fat
prejudice.
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