Study: Low-Carb Diet Best for Weight, Cholesterol
Associated Press
Wednesday, July 16, 2008
Fox News
A bigger surprise: The low-carb
diet improved cholesterol more than the other two. Some critics had predicted
the opposite.
"It is a vindication," said Abby Bloch of the Dr.
Robert C. and Veronica Atkins Foundation, a philanthropy group that honors the
Atkins' diet's creator and was the study's main funder.
However, all three approaches — the low-carb
diet, a low-fat diet and a so-called Mediterranean diet — achieved weight loss
and improved cholesterol.
The study is remarkable not only because it lasted two
years, much longer than most, but also because of the huge proportion of people
who stuck with the diets — 85 percent.
Researchers approached the Atkins Foundation with the idea
for the study. But the foundation played no role in the study's design or
reporting of the results, said the lead author, Iris Shai
of
Other experts said the study — being published Thursday in
the New England Journal of Medicine — was highly credible.
"This is a very good group of researchers," said
Kelly Brownell, director of
The research was done in a controlled environment — an
isolated nuclear research facility in
"The workers can't easily just go out to lunch at a
nearby Subway or McDonald's," said Dr. Meir Stampfer,
the study's senior author and a professor of epidemiology and nutrition at the
Harvard School of Public Health.
In the cafeteria, the appropriate foods for each diet were
identified with colored dots, using red for low-fat, green for
As for breakfast and dinner, the dieters were counseled on
how to stick to their eating plans and were asked to fill out questionnaires on
what they ate, Stampfer said.
The low-fat diet — no more than 30 percent of calories from
fat — restricted calories and cholesterol and focused on low-fat grains,
vegetables and fruits as options. The Mediterranean diet had similar calorie,
fat and cholesterol restrictions, emphasizing poultry, fish, olive oil and nuts.
The low-carb diet set limits for
carbohydrates, but none for calories or fat. It urged dieters to choose
vegetarian sources of fat and protein.
"So not a lot of butter and eggs and cream," said
Madelyn Fernstrom, a University of Pittsburgh Medical
Center weight management expert who reviewed the study but was not involved in
it.
Most of the participants were men; all men and women in the
study got roughly equal amounts of exercise, the study's authors said.
Average weight loss for those in the low-carb
group was 10.3 pounds after two years. Those in the Mediterranean diet lost 10
pounds, and those on the low-fat regimen dropped 6.5.
More surprising were the measures of cholesterol. Critics
have long acknowledged that an Atkins-style diet could help people lose weight
but feared that over the long term, it may drive up cholesterol because it
allows more fat.
But the low-carb approach seemed
to trigger the most improvement in several cholesterol measures, including the
ratio of total cholesterol to HDL, the "good" cholesterol. For
example, someone with total cholesterol of 200 and an HDL of 50 would have a
ratio of 4 to 1. The optimum ratio is 3.5 to 1, according to the American Heart
Association.
Doctors see that ratio as a sign of a patient's risk for
hardening of the arteries. "You want that low," Stampfer
said.
The ratio declined by 20 percent in people on the low-carb diet, compared to 16 percent in those on the
The study is not the first to offer a favorable comparison
of an Atkins-like diet. Research published in the Journal of the American
Medical Association last year found overweight women on the Atkins plan had
slightly better blood pressure and cholesterol readings than those on the low-carb Zone diet, the low-fat Ornish
diet and a low-fat diet that followed U.S. government guidelines.
The heart association has long recommended low-fat diets to
reduce heart risks, but some of its leaders have noted the Mediterranean diet
has also proven safe and effective.
The heart association recommends a low-fat diet even more
restrictive than the one in the study, said Dr. Robert Eckel,
the association's past president who is a professor of medicine at the
It does not recommend the Atkins diet. However, a low-carb approach is consistent with heart association
guidelines so long as there are limitations on the kinds of saturated fats
often consumed by people on the Atkins diet, Eckel
said.
The new study's results favored the Atkins-like approach
less when subgroups such as diabetics and women were examined.
Among the 36 diabetics, only those on the Mediterranean diet
lowered blood sugar levels. Among the 45 women, those on the Mediterranean diet
lost the most weight.
"I think these data suggest that men may be much more
responsive to a diet in which there are clear limits on what foods can be
consumed," such as an Atkins-like diet, said Dr. William Dietz, of the
Centers for Disease Control and Prevention.
"It suggests that because women have had more
experience dieting or losing weight, they're more capable of implementing a
more complicated diet," said Dietz, who heads CDC's nutrition unit.
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