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Default Fad Diet Wars: Low-carb v. low-fat: No clear loser, studies find

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http://www.theglobeandmail.com/servl...RB18/TPHealth/
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Low-carb v. low-fat: No clear loser, studies find
After one year, weight-loss on the two diet regimes was about the
same, researchers find

By ANDRÉ PICARD
PUBLIC HEALTH REPORTER
Tuesday, May 18, 2004 - Page A17



Over a six-month period, low-carb diets like Atkins and South Beach
result in greater weight-loss than traditional low-fat diets, but by
one year, the results are about the same for each regime, according to
two new studies.

While the research is, by no means, the final word in the fierce diet
debate, it will no doubt provide a boost to the immensely popular but
much disparaged proponents of low-carbohydrate weight-loss.

Even Walter Willett, chairman of the department of nutrition at
Harvard University and one of the world's foremost nutritional
experts, said that, based on the new research, "We can no longer
dismiss very-low-carbohydrate diets." He stressed, however, that this
should not be taken as an endorsement.

Rather, Dr. Willett said, the message to retain is that people who are
overweight should "experiment with various methods of weight control"
to find the one that works best for them and "find ways to eat [that]
they can maintain indefinitely rather than seeking diets that promote
rapid weight-loss."

Dr. Willett, the author of Eat, Drink and Be Healthy, is a proponent
of a Mediterranean-style diet rich in fresh fruits and vegetables,
fish and nuts. He believes people should consume healthy fats and
healthy carbs, and avoid refined sugars, flours and other processed
foods.

The new studies, published in today's edition of the Annals of
Internal Medicine, are the first to compare low-carb and low-fat
approaches to dieting head-to-head for a period of up to 12 months.

The first study, conducted by researchers at Duke University in
Durham, N.C., followed 120 healthy, moderately obese people over a
six-month period. During that time, average body weight dropped by 12
kilograms in the low-carb group, compared to 6.5 kilograms in the
low-fat group.

The low-carb dieters also saw greater improvements in their blood
lipids (markers for heart-disease risk), notably lower triglycerides
and higher high-density lipoproteins (good cholesterol). However, two
people in the low-carb group dropped out of the study because their
low-density lipoprotein (bad cholesterol) rose sharply and, overall,
they reported more bad reactions (such as constipation, diarrhea and
general weakness) than the low-fat group.

The second study, conducted at the Veterans Affairs Medical Center in
Philadelphia, followed 132 severely obese adults for one year. At
six-months, the low-carb group had lost more weight than the low-fat
group.

But, afterward, weight stabilized for the low-carb group, while it
continued to drop for the low-fat group.

By the one-year mark, both diets had virtually identical results, with
the low-carb dieters having lost 5.1 to 8.7 kilos, and the low-fat
group 3.1 to 8.4 kilos.

In the end, however, the low-carb dieters had better lipid readings,
particularly triglycerides and HDL cholesterol.

Linda Stern, an internist at the VA hospital and lead author of the
study, cautioned that "more research is needed to see if a
low-carbohydrate diet remains safe and effective for the longer term."

But she said the ability of people on low-carb diets to drop weight
quickly and keep that weight off was impressive, and may be a good
choice for many people.

"I think a low-carbohydrate diet is a good choice because much of our
overeating has to do with consumption of too many carbohydrates," she
said.

Gord Brethour, a retired General Motors worker who lives in Brighton,
Ont., said he was not too surprised by the new research but,
ultimately, what matters to him is practical results, not research
findings.

"You can make the numbers say whatever you want in these studies, but
the numbers on my scale don't lie," he said.

Mr. Brethour started on the South Beach diet, a low-carb regime, in
February, and since then he has lost more than 15 kilos. His doctor
has also cut the dose of his blood-pressure medication by half.

"For me, South Beach has been a success. The diets I tried before
weren't a success because I felt I was starving myself to death," he
said. Prior to taking the low-carb route, Mr. Brethour had tried three
low-fat diets, a grapefruit diet, an oat-bran diet and the Slim-Fast
plan.

Low-carb diets restrict grains, pastas, starchy vegetables, including
potatoes, and refined sugars. Mr. Brethour said that at first, he
missed staples such as potatoes and pasta, but has quickly come to
enjoy the alternatives -- fresh vegetables, beans and legumes.

"In my garden this year, I'm planting Swiss chard and spinach instead
of potatoes," he said.

An estimated one in nine adults in North America is on a low-carb
diet, and twice as many again are planning to go the low-carb route in
the coming two years, according to a recent survey.

The new research shows that one of the difficulties in judging the
effectiveness of diets, whether low-carb or low-fat, is that many
people have trouble sticking to them. In both studies, the dropout
rate was as high as 43 per cent over six months.

Mr. Brethour said he is conscious of this pitfall, but is convinced he
can keep the weight off permanently.

"I've had to change my whole style of eating. This isn't short-term
for me. I'll stick to a version of this diet permanently."

Duelling diets

Low-carb v. Low-fat: How they stack up after one year*

Results....................................Low-fat.......Low-carb

Dieters at start................................68........... .64

Still on diet at one year.......................43.............44

Weight loss..........................3.1-8.4 kilos....5.1-8.7 kilos

Dietary intakes (numbers indicate deviations from the average diet)

Calories - daily..............................-97...........-510

Protein - grams daily........................+7............-11

Carbs - grams daily.........................-22...........-131

Fat - grams daily.............................-6............+22

Fiber - grams daily...........................-1..............-5

Saturated fat - grams daily..................-4..............-2

Dietary cholesterol - grams daily..........-26............+88

Sodium - daily micrograms...............+451............-633

Average blood pressure................132/77..........139/82

Blood lipids (numbers indicate deviations from the average person)

Triglycerides - mmol/L..................+0.05...........-0.65

Cholesterol - mmol/L.....................-0.21..........+0.16

(Good cholesterol) HDL - mmol/L.....-0.13..........-0.03

(Bad cholesterol) LDL - mmol/L......-0.10..........+0.18

-*Based on a study of 132 obese adults, only 87 of whom stuck to the
diet for a full year.

SOURCE: ANNALS OF INTERNAL MEDICINE