"The war on fat has reached the point where the
systematic distortion of the evidence has become the norm, rather than the
exception," wrote Paul Campos in the Rocky Mountain News on
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As many have recognized, the "fat is unhealthy and
undesirable" premise has become preordained not just among consumers, but the
scientific community we well. The National Association to Advance Fat
Acceptance's (NAAFA) policy
on Obesity Research notes that scientific research and public policy have
historically operated with the sole goal of making fat people thin, believing
that permanent weight loss is not only possible, but that it improves health and
longevity. "Unproven assumptions about fatness frequently invalidate the basic
premise of research studies," it states.
In their comprehensive review of the scientific
evidence on obesity treatment, published by Clinical Psychology Review in 1991,
David Garner, Ph.D. and Susan Wooley, Ph.D. concluded: "Evidence that it is more
dangerous to be thin than fat is either ignored or minimized in analyses that
shape public policy toward weight loss."
But, it has been on such questionable research, or no
clinical proof at all, that our public policies on obesity have been built. In
1977, the National Institutes of Health (NIH) conference first labeled obesity a
disease, but by their 1985 conference they had upped the dangers, declaring it a
"killer disease" and suddenly making even being mildly overweight a health risk.
Along with these assertions came weight loss recommendations for this expanded
group of Americans that translated into billions of research dollars, commercial
weight-loss industry profits and doctors' revenues.
In 1998, the rhetoric became more exigent, when NIH
changed the definition of overweight
from those with BMIs (body mass indexes)
over 27, to those with BMIs of 25 or greater. That instantly deemed an estimated
29 million more Americans overweight and in need of weight loss -- folks like
Michael Jordan and Brad Pitt.
Across the nation, public health officials and
heath care industry representatives
are now declaring obesity a public health crisis.
Is it really possible that fashion ideals have
blurred the objectivity of scientific study and public policy to the point
fatness has been declared a national health crisis? Let's look at some of the
ways the evidence on obesity has been "shaped" to support the war on
obesity.
The Birth
of the 'Fat Kills 300,000' Myth
The justification for the war on obesity, used by
most government officials, healthcare providers, diet industry representatives
and special interest groups today, is that "obesity causes 300,000 deaths a
year." That figure's been repeated so often it's taken as fact. But, its origins
are a classic case of bad science run amuck.
It all started with a
Those factors, as we've seen, don't equal obesity. In
fact, Drs. McGinnis and Foege didn't even evaluate weight as a risk factor. They
also ignored other factors such as dieting and diet drug use. "Nor were
variables such as class -- poor people die sooner than the well-off -- and
social discrimination, which has been shown to have a very negative impact on
health, taken into account," Campos noted.
The researchers' numbers weren't from counting actual
deaths, but calculated using a formula for "attributable risk." They even stated
in their study that, because the articles they reviewed used different
approaches to derive estimates, their numbers "should be viewed as first
approximations."
But, subsequent researchers have taken that 300,000
figure as a foregone conclusion and it's appeared in hundreds of studies since.
Even worse, Drs. McGinnis' and Foege's "lifestyle factors" -- being sedentary
and eating poor diets -- have been misinterpreted as
"obesity."
A mountain of studies has seemed to "prove" a link
between obesity and higher mortalities. But did they really, or was it a case of
scientists seeing what they set out to find?
The largest study ever conducted, published in JAMA in January 1998, reexamined
questionnaires from an American Cancer Society study and calculated 324,135
participants' BMIs. Head researcher, June Stevens, Ph.D., claimed the relative
risks for morbidity were greater in those with higher BMIs, up until age 75, and
that the risks were greatest for younger people. Using the same data, another
report appeared in American Journal of
Epidemiology, which concluded that "obesity adds years to your real age."
These findings saturated press
releases and media headlines.
A number of their scientific peers, however, noted
significant problems with the studies, among them the recognized unreliability
of questionnaires, using figures from studies not designed to actually test for
what the researchers were later trying to extrapolate and, most notably,
difficulties in interpreting "relative risk."
Relative risk calculations don't involve clinical
testing or actually measuring anything, but are used by epidemiologists to gauge
the importance of various health problems. A relative risk of 1 means one factor
is the same as another. Stevens' stated findings were that the relative risk of
mortality from heart disease related to BMI was 1.10 in men and 1.08 in women
ages 30 to 44 years; and 1.03 in men and 1.02 in women ages 65 to 74 year old.
Reviewers were quick to condemn these inconsequential
numbers. As the National Cancer Institute has stated: "In epidemiologic
research, relative risks of less than 2.0 are considered small and usually
difficult to interpret. Such increases may be due to chance, statistical bias or
effects of confounding factors that are sometimes not evident." In other words,
the study's conclusions were flimsy. Critics also questioned the interpretation
of those numbers, noting that younger people have fewer disorders, so the
relative risk of anything would appear higher; and that there were actually no
increased risks found among those overweight, versus obese.
In an attempt to curtail the now rampant "fat kills"
legend, New England Journal of Medicine
(NEJM), editors Jerome Kassirer, M.D., and Marcia Angell, M.D. -- with 36
scientific references backing them up -- argued in two 1998 editions that
scientific and medical research did not
support the obesity-death link. "The data linking overweight and death, as
well as the data showing the beneficial effects of weight loss, are limited,
fragmentary, and often ambiguous. Most of the evidence is either indirect or
derived from observational epidemiologic studies, many of which have serious
methodological flaws. ... [T]hat [300,000] figure is by no means well
established. Not only is it derived from weak or incomplete data, but it is
called into question by the methodologic difficulties of determining which of
many factors contribute to premature death. ... Calculations of attributable
risk are fraught with problems ... when several known factors [physical
inactivity, low fitness levels, poor diet, risky weight loss practices, and
less-than-adequate access to health care, to name a few] are taken into account,
it is even possible that they account for more than 100 percent of deaths -- a
nonsensical result."
For going against what had become politically
correct, the editors were crucified in the media, by obesity researchers, and
even former U.S. Surgeon General C.
Everett Koop.
Drs. McGinnis and Foege were so concerned that their
study results were being misinterpreted they even wrote a letter in NEJM on April 16, 1998, but they, too,
were ignored by the media and most of their peers.
Researchers and public officials were increasingly
reporting not just that 300,000 deaths were linked to obesity, but suddenly caused by obesity, too. Most, like a
study published in JAMA, Oct. 27,
1999, didn't actually specify what obese people were dying from. But as the
author, David Allison, Ph.D., noted, "our calculations assume that all excess
mortality in obese people is due to their obesity."
The "fat kills 300,000" myth was
born.
Other
Troubling 'Evidence'
"In the 15 years I have been reporting this scene,"
wrote Frances Berg, M.S., editor-in-chief of Healthy Weight Journal in a
May-June, 1998 editorial, "I have often observed the risks of obesity being
exaggerated in academic and federal reports, while eating disorders,
dysfunctional eating, nutrient deficiencies, and the hazards of dangerous weight
loss they treatment are ignored or minimized."
When it comes to the war on obesity, faulty
interpretations of scientific data are rampant:
Equate
association with causation. Even
respected doctors tout
reams of numbers showing correlations between fat and heart disease or cancer to
support the obesity crisis. But just because a group of fat people have certain
health problems does not mean that their weight caused the problems. It's like
concluding that since everyone who has cancer once ate a pink cupcake, that pink
cupcakes cause cancer. It could have been a zillion other
things.
Likewise, many studies merely crunch numbers to
arrive at associations, or combine obesity with mortality figures for diabetes
or heart disease because of their "belief" that fatness caused these conditions.
Those involving clinical trials to demonstrate obesity-related causation are far
and few between. Only two conditions have been proven to be directly caused by
obesity, points out Paul Ernsberger, Ph.D., of Case Western Reserve School of
Medicine: osteoarthritis of weight-bearing joints and uterine cancer due to
obese women's higher estrogen levels and absence of proper medical attention.
Consider
only one possibility -- fatness.
When analyzing findings, to avoid incorrect conclusions the soundest studies
investigate all alternative explanations. But in studies cited as evidence for
the risks of obesity, confounding factors such as physical inactivity and
fitness levels, poor diet, socioeconomic status, race, age, and gender are often
disregarded.
Dieting is almost never considered as being a
contributing cause, even when researchers note the subjects have all lost and
regained considerable weight. Yet as we've seen, dieting and weight loss
treatments have profound impacts on mortality and illnesses. For example, a
weight loss study of previously healthy fat men led by E. J. Drenick, M.D., in
the Feb. 1, 1980, JAMA, concluded:
"It appears that no unusual factors other than obesity could have caused such
extraordinary [referring to a 12 times
greater] mortality."
Finding fat populations in developed countries who
haven't dieted is next to impossible in today's thin obsessed world. But back in
the 1960s, researchers at the University of Oklahoma found communities of
Italian-Americans who were happy with their weights -- many were very fat and
ate plenty of rich high-cholesterol foods -- and virtually free of all the
diseases supposedly attributed to fatness. Even as early as 1952, the Mayo
Clinic found that fat people who stayed fat had a better chance of surviving a
coronary than slim people or those who tried to diet. Numerous similar findings
were found during the 1960s, before dieting became pervasive.
Conclude
study results inconsistent with the data. When it comes to obesity, regardless of the data,
researchers oftentimes conclude what they set out to prove. They know most
people will merely skim the abstract anyway, or the media will do it for
them.
For example, an American Cancer Society study
published in this year's April issue of NEJM claimed
to find irrefutable evidence of increased cancer deaths in higher BMIs and that
90,000 lives could be saved from cancer if BMIs were under 25 throughout a
lifetime. In actuality, critics noted, the data found the lowest cancer risk in
those with BMIs 25 to 29.9 (considered overweight), a fact also omitted from all
major media stories. The risks were negligible in overweight and obese patients
until subjects reached a BMI of 40 and above, and even then, extremely obese
women had lower cancer risks than the
slimmest men.
Generalize
results from one studied group to broad populations. Like that cancer study, the negative health
consequences of obesity appear to largely afflict those at extreme levels of
obesity, BMIs of 40 or greater, which is a mere 4.7 percent of the population. Despite
the fact a small fraction of Americans are most at health risk from obesity,
everyone's told they need to lose weight. And, most diets are directed towards
women, although the negative health consequences of fatness are most serious in
men.
In women with BMIs of 40 and above, their life
expectancy is reduced by 5 years, Ernsberger said. "Yet these extremely obese
women still have a longer life
expectancy than normal-weight
men."
Few studies have been done on minority populations or
those with BMIs over 40, leaving scientists to mostly speculate as to the actual
risks in these groups.
Where's
the Epidemic?
Sensationalizing statistics and exaggerating claims
of a crisis aren't found in sound scientific inquiry, as neutrality and reasoned
analysis are fundamental. So not surprisingly, despite all the hysteria behind
the "epidemic of obesity" supposedly threatening our nation, and now the world,
many experts have found it's been blown all out of proportion.
Not only is the term "overweight" arbitrary,
unrelated to health, and been redefined over the years, it's used
interchangeably with "obese" to heighten the crisis. Everyone with BMIs of 25 or
greater are lumped together with the minority of those extremely obese to
comprise the "more than half of U.S. adults" considered fat, as did the study
led by Aviva Must, Ph.D., in the October 27, 1999, issue of JAMA.
Yet, do those rising numbers of fat Americans
actually translate to an individual or national health crisis? Hardly. Because
the incidence of obesity is defined as a threshold, a small increase in average
weights has a disproportionate effect, Jeffrey M. Friedman, M.D., Ph.D., at
Rockefeller University, explained in a Feb. 6, 2003, press release. Although the
incidence of obesity in the United States has increased from 23.3 percent in
1991 to 30.9 percent today, the weight of the average American has increased
only 7 to 10 pounds on average, he pointed out.
Furthermore, it's a strange epidemic that finds those
exposed to it living longer, healthier lives than ever before. Yet, that's
exactly what Department of Health and Human Services statistics show, even as
the population is getting fatter and simultaneously aging. Given that the NIH
and WHO have claimed obesity is second only to smoking as a preventable cause of
death, then increases in adult obesity should have a negative impact on life
expectancy, Ernsberger noted. "The opposite is true. Death rates have fallen.
The greatest improvements are in cardiovascular disease deaths, which are most
strongly linked to obesity," he said. "The decline in age-related mortality for
stroke is 59 percent from 1970 to 1994; for heart disease, 53.2 percent."
As for the $93 billion [to $117 billion, depending on
whose figures you want to use] "costs" of obesity? Mere hype. With doctors,
researchers and politicians attributing everything that happens to fat people as
the fault of their fatness, medical expenses for all of their health problems
are included, Glenn Gaesser, Ph.D., associate professor of exercise physiology
at the University of Virginia, has noted. A closer look reveals these dollar
cost estimates also tally ambiguous tabs of "reduced productivity," absenteeism,
higher insurance premiums, litigation and even the ineffective weight loss
treatments they themselves promote.
Cautionary
Note
NAAFA observed in its Obesity Research policy
statement, that the leading obesity researchers all have enormous economic
stakes in seeing expanded forms of obesity treatment applied to more
Americans.
Oftentimes the most knowledgeable experts are within
industries. That's not always a problem. But in the case of obesity, Thomas
Moore, M.D., of Boston University School of Medicine, observed, "Due to their
economic interests and bias, a suppression of research antithetical to the diet
industry's position exists. Research not supporting weight loss isn't funded and
isn't published."
In any event, as Campos wrote in the New
Republic in January: "[T]he conventional wisdom about fat in the United
States is based on factors that have very little to do with a disinterested
evaluation of the medical and scientific evidence, and therefore this
conventional wisdom needs to be taken for what it is: a pervasive social myth
rather than a rational judgment about risk."
On Friday:
Are there benefits to middle-age
spread?
