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The World's Biggest Fad Diet
(and why you should probably avoid it)
by Dean Esmay
The most common belief about diet in the United States today is that
excessive fat in the diet is the primary cause of obesity, heart
disease, and other health problems. This belief is extraordinarily
widespread in both the popular imagination and in the medical community,
and most especially among popular writers on diet. Consumer advocacy
groups, professional medical organizations, and government health
organizations almost universally endorse this concept. You can't even
listen to stand-up comics talk about health or fat people without
hearing a joke about fatty foods. The belief that fat is the dietary bad
guy is about as close to universal as any idea in America.
And yet there has long been evidence that the danger of dietary fat may
be greatly exaggerated. Unbeknownst to the general public, the theory
that bad health follows high intake of fats in general or saturated fats
in particular has long had its detractors--and the list of detractors
has been growing noticeably in recent years.
The idea that saturated fats cause heart disease is completely wrong,
but the statement has been 'published' so many times over the last three
or more decades that it is very difficult to convince people otherwise
unless they are willing to take the time to read and learn
what...produced the anti-saturated fat agenda. (Dr. Mary Enig,
Consulting Editor to the Journal of the American College of Nutrition,
President of the Maryland Nutritionists Association, and noted lipids
researcher.)
Despite abundant evidence that dietary fat bears no relation to
development of cancer of the breast, the NIH intends...to try once again
to prove a link that is probably not there....Why then does NIH insist
on spending $10 million on a study whose hypothesis seems to be little
more than wishful thinking? Is it only because of the faddish
infatuation with fat as the root of all dietary evil? (Editorial in
NATURE, Vol. 359, 29 October 1992.)
The diet-heart hypothesis [that suggests that high intake of saturated
fat and cholesterol causes heart disease] has been repeatedly shown to
be wrong, and yet, for complicated reasons of pride, profit and
prejudice, the hypothesis continues to be exploited by scientists,
fund-raising enterprises, food companies and even governmental agencies.
The public is being deceived by the greatest health scam of the century.
(Dr. George V. Mann, participating researcher in the Framingham study
and author of CORONARY HEART DISEASE: THE DIETARY SENSE AND NONSENSE,
Janus Publishing 1993.)
In Framingham, Massachusetts, the more saturated fat one ate, the more
cholesterol one ate, the more calories one ate, the lower people's serum
cholesterol...we found that the people who ate the most cholesterol, ate
the most saturated fat, ate the most calories weighed the least and were
the most physically active. (Dr. William Castilli, Director of the
Framingham Study. Archives of Internal Medicine, 1992.)
Call it the Big Fat Lie. Fat has, through no real fault of its own,
become the great demon of the American dietary scene. It is no myth that
one-third of Americans are overweight. It is, however, a myth that
Americans are overweight due to excessive fat consumption. (Dr. Richard
K. Bernstein, Type I Diabetic and noted diabetic researcher.)
Another extremely popular view has long held that the key to weight loss
for the chronically overweight is to view fat as the enemy. The popular
belief can often be phrased in this simple formulation: "Eating fat
makes you fat, eat less fat and you'll be less fat." Although this
simplistic view is no longer commonly embraced by most nutritionists, a
surprising number of health professionals, personal trainers, and
weight-loss gurus continue to make this claim to a public eager to shed
its extra pounds.
More conservative dietary authorities stopped making the claim that
cutting fat intake would automatically lead to weight loss (or easy
weight management) a few years ago. The more conservative low-fat
advocates now restrict their claims only to saying that fat has more
calories than protein or carbohydrate, and therefore cutting fat is an
easy way to cut down on calories without feeling hungry. But there is a
significant and growing amount of evidence to question even this more
cautious view.
There is evidence that altering the proportion of the calories in the
diet from fat, carbohydrate, and protein can have a limited effect on
weight loss; however the effects appear to be quite small. (Methods for
Voluntary Weight loss and Control, NIH Technology Assessment Conference
Panel, Annals of Internal Medicine June 1992, 116;11)
A growing number of authors, most of them medical doctors or people with
doctorates in fields such as biology or biochemistry, have recently
exploded onto the American diet scene with popular books offering easier
weight loss and substantial health benefits from diets higher in fat,
higher in protein, and significantly lower in carbohydrate than the
popular low-fat diets. Time and more research will probably tell whether
the likes of Dr. Robert Atkins, Dr. Barry Sears, Drs. Rachael and
Richard Heller, Drs. Mary Dan and Michael R. Eades, and other diet book
authors who go against the prevailing views on diet are right or wrong.
Nevertheless it's astonishing how frequently and even viciously these
people who question the reigning dietary dogma are dismissed, even
angrily attacked, by defenders of the low-fat diet. In the meantime,
evidence that low-fat diets are by and large ineffective and possibly
even dangerous continues to accumulate in some of the world's most
prestigious medical journals.
Low-fat diets are ineffective
Low-fat (30% or less total calories daily from fat) diets are generally
eaten with a low intake of protein (around 15% is typical) and a very
high intake of carbohydrates (60% or more is usually considered
"healthy" by low-fat diet gurus).
And yet there is a good deal of evidence that such diets are ineffective
for weight loss, may in fact even cause weight gain in some individuals,
and that they are completely unnecessary for most individuals seeking to
improve their health.
A recent study involving over 40,000 middle-aged and older American men
over a period of six years found that there was no link between
saturated fat intake and heart disease in men. It also supported the
contention that linolenic acid (a form of fat) is preventive against
heart disease. (Ascherio A et. al. Dietary fat and risk of coronary
heart disease in men: cohort follow up study in the United States.
British Medical Journal, 1996 Jul 13, 313:7049, 84-90.)
The average U.S. daily fat consumption is 2.52 ounces, with 10% of males
obese; the average Australian daily fat consumption is much less, but
14% are obese. (LONGEVITY, May 1992)
Even with extreme changes in the fat-carbohydrate ratio (fat energy
varied from 0% to 70% of total intake), there was no detectable evidence
of significant variation in energy need as a function of percentage fat
intake. (Leibel RL. Energy intake required to maintain body weight is
not affected by wide variation in diet composition. American Journal of
Clinical Nutrition 1992;55;350-5)
We found no evidence of a positive association between total dietary fat
intake and the risk of breast cancer. There was no reduction in risk
even among women whose energy intake from fat was less than 20 percent
of total energy intake. In the context of the Western lifestyle,
lowering the total intake of fat in midlife is unlikely to reduce the
risk of breast cancer substantially. (Hunter, DJ et. al. Cohort studies
of fat intake and the risk of breast cancer - A pooled analysis. New
England Journal of Medicine, 334: (6) FEB 8 1996)
In the presence of dietary carbohydrate, the preferred fuel is glucose
and the capacity to mobilize fat is limited. Factors that increase blood
glucose during dieting may stimulate insulin release and all the
metabolic sequelae of circulating insulin. Fatty acid synthesis is
activated and lipolysis is profoundly inhibited by insulin even at very
low concentrations of the hormone. (American Journal of Clinical
Nutrition 1992;56:217S-23S) [Note: Fatty acid synthesis is the creation
of body fat. Lopolysis is the burning of body fat.]
At least so far as the risk of heart disease goes, the simple fact is
that there is no longer any proof that lowering fat (or cholesterol)
intake offers any protection whatsoever against heart disease. This is
perhaps best summed up by Drs. Laura A. Corr (Consultant Cardiologist to
Guy's and St. Thomas' Hospitals, London U.K.) and M.F. Oliver (of the
National Heart and Lung Institute in London, U.K.), in the concluding
paragraphs of their recently-published review of all studies to date of
low-fat or low-cholesterol diets as a treatment for heart disease:
The commonly-held belief that the best diet for prevention of coronary
heart disease is a low saturated fat, low cholesterol diet is not
supported by the available evidence from clinical trials. In primary
preventions, such diets do not reduce the risk of myocardial infarction
or coronary or all-cause mortality. Cost-benefit analyses of extensive
primary prevention programmes, which are at present vigorously supported
by governments, health departments, and health educationalists, are
urgently required....Similarly, diets focused exclusively on reduction
of saturated fats and cholesterol are relatively ineffective for
secondary prevention and should be abandoned. There may be other
effective diets for secondary prevention of coronary heart disease but
these are not yet sufficiently well defined or adequately tested.
(European Heart Journal, Volume 18, January 1997.)
Furthermore, despite more than a decade of American diet gurus
recommending low-fat diets for weight loss, there remains no study which
clearly shows that low-fat diets result in long-term, significant weight
loss among the chronically obese. In fact, most such studies show quite
marginal improvements in weight, and some actually show significant
weight gain among test subjects.
In a two-year study, 171 women on a low-fat diet achieved a maximum
weight loss of only about seven and a half pounds at 6 months, and by
year two some of that weight was regained. Most significantly, the
standard deviation was more than twice the average weight loss, showing
that a number of subjects actually gained weight on the low-fat diet,
not counting the 13 that dropped out of the program. (Sheppard L et. al.
Weight Loss In Women Participating in a Randomized Trial of Low-Fat
Diets. American Journal of Clinical Nutrition 1991;54:821-8.).
As astonishing as this may sound, it's in no way surprising to those
who've spent much time reviewing the scientific literature. The truth is
that not one clinical study has ever shown that low-fat diets allow
long-term reversal of obesity in most subjects, whether combined with
exercise or not. Perhaps most damning of all, according to the USDA,
Americans' fat consumption has consistently gone down over the last 20
or so years while the American national rates of obesity have gone up at
precisely the same time. Correlation is not causation, and yet it hard
to jive this fact with claims that lowering fat intake helps those who
are overweight to reduce their body fat, or the widespread claim that
lowering fat intake makes it possible to eat more food without gaining
weight. Some explanations have been offered to continue to support the
low-fat paradigm as a workable weight-loss diet, but none are very
compelling and none have strong clinical support.
In the adult US population the prevalence of overweight rose from 25.4%
from 1976 to 1980 to 33.3% from 1988 to 1991, a 31% increase. During the
same period, average fat intake, adjusted for total calories, dropped
from 41.0% to 36.6%, an 11% decrease. Average total daily calorie intake
also tended to decrease, from 1,854 kcal to 1,785 kcal (-4%). Men and
women had similar trends. Concurrently, there was a dramatic rise in the
percentage of the US population consuming low-calorie products, from 19%
of the population in 1978 to 76% in 1991. From 1986 to 1991 the
prevalence of sedentary lifestyle represented almost 60% of the US
population, with no change over time...Reduced fat and calorie intake
and frequent use of low-calorie food products have been associated with
a paradoxical increase in the prevalence of obesity. (Heini AF; Weinsier
RL. Divergent trends in obesity and fat intake patterns: the American
paradox.) American Journal of Medicine, 1997 Mar, 102(3):259-64)
(Note: I'm interested in hearing about any scientific literature which
DOES support the low-fat diet as an effective weight-loss diet; if you
have any please email me at esmay@syndicomm.com).
Low-fat diets are dangerous
Not only is there a great deal of reason to question the belief that
low-fat diets improve health or give significant help in weight loss
efforts, but there is a growing amount of evidence that such diets are
actually quite unhealthy, raising the risk of heart disease, diabetes,
and cancer, not to mention certain psychiatric disorders such as
depression and schizophrenia.
A recent American study showed that low-fat, high-carbohydrate diets
(15% protein, 60% carbohydrate, 25% fat) increase risk of heart disease
in post-menopausal women over a higher fat, lower carbohydrate diet (15%
protein, 40% carbohydrate, 45% fat). (Jeppeson, J., et. al. Effects of
low-fat, high-carbohydrate diets on risk factors for ischemic heart
disease in postmenopausal women. American Journal of Clinical Nutrition,
1997;65:1027-33)
The largest and most comprehensive study on diet and breast cancer to
date, studying over 5,000 women between 1991 and 1994, showed that women
with the lowest intake of dietary fat had a significantly higher
incidence of breast cancer than the women with the highest intake of
dietary fat. It also found that women with the highest intake of starch
had a significantly higher incidence of breast cancer than the women
with the lowest intake of starch. The study found no evidence that
saturated fat had any effect one way or the other on breast cancer, and
that unsaturated fat had a significantly protective effect against
breast cancer. (Franceschi S et. al. Intake of macronutrients and risk
of breast cancer. Lancet; 347(9012):1351-6 1996)
A study involving tens of thousands of American women showed that diets
high in carbohydrate (which almost all low-fat diets are) significantly
raise women's risk of developing diabetes, although cereal fibre intake
seems to have a limited protective effect. (Jorge Salmeron et. al.
Dietary Fiber, Glycemic Load, and Risk of Non-insulin-dependent Diabetes
Mellitus in Women. Journal of the American Medical Association.
1997;277:472-477)
High intake of fats from the Omega-3 group increase HDL cholesterol,
which is considered protective against heart disease. Obviously it would
be difficult to eat an Omega-3 rich diet while following a traditional
fat reduced diet, especially if one were following one of the popular
American diets that has one eating only 20-30 grams of fat per day. (Franceschini
G. et. al. Omega-3 fatty acids selectively raise high-density
lipoprotein 2 levels in healthy volunteers. Metabolism, 1991 Dec, 40:12,
1283-6. See also Journal of the American College of Nutrition
1991:10(6);593-601)
A strong correlation exists between schizophrenia and deficiencies in
fats, especially in the n-3 series. Schizophrenics who naturally eat
lots of Omega-3 fats tend to have less severe symptoms than those who
don't. Supplementation with extra fats in the Omega-3 group
significantly improves symptoms of schizophrenia in most patients. Close
relatives of schizophrenics show similar deficiencies in Omega-3 fats.
The possibility that diets generally low in fat might worsen
schizophrenia or even bring on the condition among those already
predisposed to it is hard to ignore. (Laugharne JD; Mellor JE; Peet M.
Fatty acids and schizophrenia. Lipids, 1996 Mar, 31 Suppl:, S163-5. See
also Peet M et. al. Essential fatty acid deficiency in erythrocyte
membranes from chronic schizophrenic patients, and the clinical effects
of dietary supplementation. Prostaglandins Leukot Essent Fatty Acids,
1996 Aug, 55:1-2, 71-5)
Our results do not support the recommendation of an isoenergetic high
carbohydrate, low fat diet for improving peripheral insulin action in
adults with glucose intolerance ... the increase in insulin action that
we observed previously with vigorous exercise training was negated when
combined with a diet high in carbohydrates and fiber. ... The subjects
in this study are at increased risk for developing NIDDM. (American
Journal of Clinical Nutrition 1995;62:426-33) [note: NIDDM is
Non-Insulin Dependent Diabetes Mellitus -- the most common form of
diabetes.] Low-fat high-carbohydrate diets eaten by patients with
diabetes (NIDDM) have been shown to lead to higher day-long plasma
glucose, insulin, triglycerides, and VLDL-TG, among other negative
effects. In general, study has demonstrated that multiple risk factors
for coronary heart disease are worsened for diabetics who consume the
low-fat, high-carbohydrate diet so often recommended to reduce these
risks. (Chen YD et. al. Why do low-fat high-carbohydrate diets
accentuate postprandial lipemia in patients with NIDDM? Diabetes Care,
1995 Jan, 18:1, 10-6)
Conventional wisdom holds that low fat diets improve insulin
sensitivity. Unfortunately, this is true only after an ultra-low
carbohydrate diet. No changes in glucose tolerance and substrate
oxidation were measured after a high-carbohydrate low fat diet. In
addition, these studies confirm a growing body of evidence that
increasing dietary carbohydrate increases plasma triglycerides and
decreases plasma high-density-lipoprotein (HDL), increasing the risk of
cardiovascular disease. (Metabolism 1993:42:365-70)
Numerous studies have shown that high-carbohydrate low-fat diets lead to
high triglycerides, elevated serum insulin levels, lower HDL cholesterol
levels, and other factors known to raise the risk of coronary artery
disease. (See Liu GC; Coulston AM; Reaven GM. Effect of
high-carbohydrate low-fat diets on plasma glucose, insulin and lipid
responses in hypertriglyceridemic humans. Metabolism, 1983 Aug, 32:8,
750-3. See also Coulston AM; Liu GC; Reaven GM. Plasma glucose, insulin
and lipid responses to high-carbohydrate low-fat diets in normal humans.
Metabolism, 1983 Jan, 32:1, 52-6. See also Olefsky JM; Crapo P; Reaven
GM. Postprandial plasma triglyceride and cholesterol responses to a
low-fat meal. American Journal of Clinical Nutrition, 1976 May, 29:5,
535-9. See also Ginsberg H et. al. Induction of hypertriglyceridemia by
a low-fat diet. Journal of Clin Endocrinol Metab, 1976 Apr, 42:4,
729-35)
Is That All?
The references given above do not represent all the evidence against the
low-fat diet as a worthless, possibly dangerous, diet. They represent
merely a sampling of some of the more relevent studies. Below is some
recommended reading for those interested in learning more on the
subject.
The simple fact of the matter is that the low-fat diet is a fad diet.
Warnings about the dangers of fat in the diet are constant in the media.
Fat-phobia is ubiquitous among health-conscious Americans, and a
surprising number of people from all walks of life (including most
health professionals) continue to recommend a low-fat diet and to preach
the "dangers" of fat. Such messages often take on an almost hysterical,
or even belligerant, tone. Yet a growing mound of scientific data not
only suggests that this diet fad is pointless, but suggests that it may
actually be dangerous to the health of millions of Americans and others
worldwide.
Recommended Books:
I recommend the following books for popular references on alternatives
to the low-fat diets. Diabetics especially are urged to see the
Bernstein book.
* THE NEW DIET REVOLUTION by Dr. Robert Atkins.
* PROTEIN POWER by Drs. Michael R. and Mary Dan Eades
* THE CARBOHYDRATE ADDICT'S LIFESPAN PROGRAM by Drs. Rachael and Richard
Heller.
* THE ZONE by Dr. Barry Sears
* DR. BERNSTEIN'S DIABETES SOLUTION by Dr. Richard Bernstein
This document copyright 1997 by Dean Esmay. |
