Hannah Gruen wrote:
"Cookie Cutter" wrote
I read in one report that the low carb group started out at 20 grams of
carb (with a focus on vegetable sources of protein and fat) and increased
their intake over the two years to around 110 grams. It sounds like,
toward the end of the study, that the low-carb and Med diets might have
been fairly similar. I can't figure out what these people would be eating
if they were minimizing/abstaining from meat, cheese, eggs, etc. Israel
is in the Middle East. Surely, a Mediterranean style diet is closest to
what they would normally eat and most would probably aim as close to what
they would be traditionally eating as the confines of their diet group
allowed. At 110 grams, they could work in beans, pasta, many wheat-based
dishes, etc.
I think that trying to solve the "mystery" of the results is probably
hopeless. Kind of a "What Did They Eat? And When Did They Eat It?"
conundrum.
Yes, I've been reading more about this one, too. Even more puzzling (to me)
is the fact that the calories were restricted for the low-fat and
Mediterranean diet groups, but not for the LC group.
I think that the idea was that higher protein adn fat consumption and
lower carb consumption of LC diet suppresses appetite so that LC group
kind of automatically and voluntarily reduces its calories. It seems to
have also worked that way.
My guess would be that
as the LC group started adding back carbs, they lost the natural appetite
suppresant function of the diet and calories may have increased? Not sure,
as I haven't read the full study or perused the data. If total calories in
is substantially different for the different groups, that can make a
difference in findings that may trump effects of macronutrient diet makeup.
If you look at
Table 2. Changes in Dietary Intake, Energy Expenditure, and Urinary
Ketones during 2 Years of Intervention
http://content.nejm.org/cgi/content/full/359/3/229/T2
you'll see that calorie reductions in LC and LF groups were almost
identical. In the Mediterranean group the reductions were a little
smaller, but still not statistically significantly different from
LC and LF groups.
At any rate, it seems like it would have been a good idea to keep as many
parameters as possible equivalent, if they wanted to compare diets. Like
calories, for instance.
As I mentioned, the realized calorie reductions were not statistically
significantly different between groups, and in LC and LF groups they
were almost identical.
Sometimes I read these research designs, and wonder
who on earth reviewed and approved them. They just defy logic.
Anyway, it's just not a well-designed study, IMO, even if it does show
advantage for the lower-carb plans (no surprise there.)
I have to disagree with you. Although not completely without flaws,
this is, however, a large, long term (2 years), well-designed and
well-published (NEJM) study, which compared well-designed and
well-known diets. Additionally, if it wasn't well-designed, it
probably wouldn't have been published in NEJM, the number one
medical journal in the world.
Here's an interesting excerpt from
Low-fat Diets May Not Be Best For Weight Loss, Study Suggests
http://www.sciencedaily.com/releases/2008/07/080716171134.htm :
"Dr. Iris Shai is a researcher at the S. Daniel Abraham
International Center for Health and Nutrition in the Department of
Epidemiology at Ben-Gurion University of the Negev. She conceived
the study with Dr. Stampfer, the senior author, while she was a
Fulbright fellow at Harvard School of Public Health and Channing
Laboratory in Boston, Massachusetts."
Dr. Meir Stampfer is one of the authors of the study in question and
a very remarkable scientist. Harvard's press release
HSPH Department Chairs Meir Stampfer and Walter Willett Most Cited
Scientists of the Decade in Clinical Medicine
Harvard School of Public Health Press Release, Friday, September 23,
2005
http://www.hsph.harvard.edu/press/releases/press09232005.html
from September 23, 2005, writes about him as follows:
"Meir Stampfer, Chair of the Department of Epidemiology at the
Harvard School of Public Health (HSPH) has been ranked the number
one most cited scientist in clinical medicine for the last decade.
According to ISI Essential Science Indicators, 376 of his published
research findings were cited nearly 31,000 times between 1995 and
August of 2005."
Dr. Stampfer's web page at Harvard:
Meir Stampfer
Professor of Nutrition and Epidemiology
Department of Epidemiology
Department of Nutrition
http://www.hsph.harvard.edu/faculty/meir-stampfer/
I wonder, if a major force like Stampfer would have allowed his name
to be used in this study, if there were any doubts about its quality.
--
Matti Narkia
http://ma.gnolia.com/groups/Nutrition