In The News
Weight Loss with a
Low-Carbohydrate, Mediterranean, or Low- Fat Diet: Diet
Face-off in the New England Journal of Medicine
Yes,
there is still more to say about the research study
published in the NEJM on July 17, 2008. There are the
facts of the study and the spin as reported in the
media. I will touch on both.
A few
important points regarding the design of this 2 year,
randomly assigned study comparing the American Heart
Association (AHA) diet with a Mediterranean and a low
carb diet:
-
The
AHA and Mediterranean diets were calorie-controlled:
men 1800 per day, women-1500 per day. Although the
low-carb arm did not limit calories, the
participants naturally lowered their intake due to
the satiating effects of higher protein and fat.
-
The
AHA diet recommended no more than 30% of calories
from fat and less than 10% of that in saturated fat.
-
The
Mediterranean diet was moderate in fat (no more than
35% of calories), low in red meat, concentrating on
fats from olive oil and nuts.
-
The
low carb arm was based on Atkins induction and did
not limit the amount of fat including natural
saturated fat. For 2 months the Atkins group limited
carbs to 20 grams as outlined in Dr. Atkins book.
For the next 4 months the participants followed the
carb ladder, gradually increasing carb intake. After
6 months and for the remainder of the study this
group was advanced to 120 grams of carbs daily. This
was not a “vegetarian version” of Atkins as has been
reported but based on Atkins induction. This
information was obtained directly from one of the
main researchers Dr. Iris Shai, R.D., Ph.D.
This is
the first trial comparing diets of different ratios of
fat, protein and carbohydrate lasting 2 years. This
study had a very high completion rate. Weight loss
studies generally have high drop-out rates. It was done
in a relatively controlled environment with all groups
receiving dietitian support and follow-up.
The Results
-
All
groups lost weight. By the end of 2 years those who
completed the study on the AHA diet lost an average
of 7.26 lbs, Mediterranean diet an average of 10.12
lbs., and low-carb an average of 12.1 lbs.
-
There were no differences between groups in the
amount of change in the LDL or so-called “bad
cholesterol”.
-
The
greatest increase in the HDL or “good cholesterol”
occurred in the low carb group.
-
The
greatest drop in triglycerides occurred in the low
carb group.
-
The
cholesterol to HDL ratio improved in the low carb
group by 20%, Mediterranean diet by 16% and the AHA
diet by 12%.
-
The
best improvement in an important inflammation
marker, CRP, occurred in the low carb group.
-
The
Mediterranean diet decreased the fasting blood sugar
the most while it increased in the AHA group!
The low carb group also improved blood sugar but to
a lesser degree than the Mediterranean diet.
However, after 24 months the best improvement in A1C
(a measure of long-term glucose control) occurred in
the low carb arm.
Discussion
This is
not the first time results such as these have been
demonstrated with an Atkins lifestyle. This long-term
study can be added to mounting data that this program is
both safe and effective. The “dangerous” side effects so
often mentioned by critics have not been demonstrated in
any of the research done over the years.
It is
worth noting that the AHA diet did not do better than
either low carb or the Mediterranean diet in any
respect!
After
6 months those on the low carb arm were advanced to 120
grams of carbs daily. This is more than most people who
are at their goal weight would be able to eat on the
maintenance phase of their plan. Yet despite the oft
repeated criticism that people might be able to lose
weight on Atkins but when they stop losing the diet will
be bad for the heart, has not been borne out.
Cardiovascular risk factors were still better with low
carb even after weight loss stopped. This is an
important finding.
There
is one puzzling finding in this study that differs from
others done with low carb and people with diabetes. The
fasting blood sugar dropped more with the Mediterranean
diet than on low carb. Other studies have demonstrated a
significant and rapid improvement in blood sugar similar
to results seen when using a low-carb lifestyle
clinically. In fact, the blood sugar improvement can be
so immediate that people are cautioned to work with
their doctors to avoid a dangerous drop in blood sugar
due to over-medication.
There
may be several reasons why the improvement in this study
wasn’t as expected. It appears that the Atkins group had
a larger number of people on meds for diabetes than the
other arms which may imply that their diabetes was more
long-term and severe. The amount of carbs allowed in the
study protocol was higher than one would use in someone
with diabetes. As explained in
Atkins Diabetes
Revolution the amount of carbs is
kept very low until there is significant improvement in
blood sugar levels and a good amount of weight is lost.
Clearly, Atkins is personalized when used in a clinical
setting that may not fit into a research protocol.
As for
the issue of the dreaded saturated fat, it is worth
noting that the participants doing low carb ate more
natural saturated fat but still had the best weight loss
and better lipid improvements than the other groups.
This finding will of course be ignored by the “saturated
fat is bad group”. In fact, not surprisingly, the 10%
fat Ornish group was quick to distance themselves from
this study stating that 30% fat is way above their
recommendation of not more than 10% fat intake as the
only way to be healthy.
Researchers’
comments on their study
In the
discussion section of their study a number of important
take-home points were made:
-
Both the low-carb and Mediterranean diets are
effective alternatives to low-fat and appear to be
just as safe.
-
Both low-carb and Mediterranean diets have
beneficial metabolic effects suggesting that in
clinical practice diets be individualized to
metabolic needs and personal taste.
-
Since all three groups reached similar calorie
intakes (the low carb group without a mandated
calorie restriction) low-carb may work best in those
who are unable to follow a calorie-restricted plan.
-
Increasing improvements in health markers seen
during the 2 years of the study, even though the
maximum weight was lost by 6 months, implies that a
healthy diet, including low-carb, has benefits
beyond just the weight loss attained.
-
The
behavioral approaches that assisted in weight loss
were similar to results obtained with drug therapy.
-
Results in a number of biomarkers measured appear to
be a result of the differing diet compositions. The
results imply that dietary composition modifies
metabolic biomarkers in addition to leading to
weight loss.
How
it’s been reported
The
results of this study have been spun any number of
ways.
Dr.
Ornish, as already mentioned, thinks the only diet for
everyone is a diet with virtually no saturated fat and
not more than 10% total fat.
The AHA
spokesperson responded that the most recent AHA
guidelines have changed. They have moved away from
limiting fat to 30% of total calories to between 25 to
35% of “healthy fats” while cutting the saturated fat
recommendation from 10% to 7% of total calories. He
neglected to mention on what evidence the stricter
saturated fat restriction was made and how the public
can use this info. Since saturated fat is supposed to
increase LDL cholesterol this study found no differences
in LDL changes between the three diets. How does he
explain that?
He did
acknowledge the low carb group lost more weight but
still claims that a diet high in saturated fat might
do harm to blood vessels and the heart over time. Nor
did the spokesperson comment on the fact that lipid
parameters were better with low carb than with low fat
and that the low fat arm increased fasting blood sugars
in those with diabetes: a problematic finding since
heart disease is a major complication of diabetes.
Others
pointed out the Atkins group didn’t eat the usual cheese
and bacon buffet that they think is Atkins but had
better results because it was a vegetarian version.
Sorry people, it was Atkins from the book and the
results were still better with higher saturated fat.
Many
focused only on the
weight loss with no mention of the
other important benefits. I was particularly unhappy
with the report by Dr. Tim Johnson on Good Morning
America. He ridiculed the two pound difference between
the Mediterranean diet and low carb while ignoring the
AHA result coming in at a distant third. He did not
mention that the low carb arm didn’t mandate a calorie
restriction and had an increased carb intake after 6
months which would stop or slow weight loss. I found his
comments a particular disservice to people struggling
with weight. We know that losing 5 to 10% of excess
weight can decrease risk factors and should be
encouraged as an important goal. In my opinion, Dr.
Johnson lost an important opportunity to educate the
public but rather chose to minimize the results of this
research.
Several other articles including medical education
pages on the Internet headlined that low-carb and
Mediterranean diets may equal watching fat intake except
that they didn’t--- they did better all around.
A few
called the study highly flawed because it was partially
funded by the Dr. Robert C. and Veronica Atkins
Foundation. As if that automatically implied tampering
with the design or the results of the study. Sorry, none
of that happened. It is doubtful that the researchers
and institutions involved would be willing to damage
their careers or integrity for a relatively small amount
of money.
One
obesity researcher did called the study highly credible.
My
comments
What we
see is that anything positive about an Atkins type
program is a lightening rod. When there was no research
on Atkins it was criticized because there was no
research. We were told any number of bad things would
happen based purely on supposition. None of this has
been shown to be true. Rather, as has been seen for
decades in both clinical practice and consumer use, it
is a safe and effective lifestyle.
After
the first studies were published with positive results
the criticism was that studies were too short. Critics
were sure there would be damaging long-term effects or
positive results would disappear once weight loss
stopped. Now we have a two year study and it still comes
out on top.
It’s
time to include the Atkins lifestyle as a proven,
doable, healthy and effective choice to combat obesity.
It’s time to stop thinking one-size-fits-all and
encourage the diet that a person can turn into a
permanent lifestyle change. Instead of focusing on rapid
scale loss, focus on inch loss and health benefits. Keep
the bigger picture in mind. It’s time we all began to
take responsibility for the only body we will ever have
and make the change that works for you while supporting
others who choose the one that works for them.
In my
opinion and experience, people with a family history of
diabetes, addiction to carbs, increasing belly fat or
those at risk for
metabolic syndrome,
can address these issues best with a low-carb approach.
Educate
yourself about the approach you choose and get as much
support as you can. There are many low-carb sites and
forums to make the process easier. Take advantage of
them and remember you’re in it for the long haul.
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The information presented on this site is in no way
intended as medical advice or as a substitute for medical treatment.
This information should be used in conjunction with the guidance and
care of your physician. Consult your physician before beginning this
program as you would any weight-loss or weight-maintenance program.
Those of you on diuretics or diabetes medication should proceed only
under a doctor’s supervision as changing your diet usually requires a
change in medication dosages. As with any plan, the weight-loss phases
of this program should not be used by patients on dialysis or by
pregnant or nursing women. As with any weight-loss plan, we recommend
anyone under the age of 18 follow the program under the guidance of
their physician.