After a six-
on the Atkins
diet lost 15
on the more
diet lost seven
had kept off
Low-Carb Diets Does Science Support Them?
Finally, a recent review of medical studies
(from approximately 40 years ago to the
present) has found that cutting carbohy-
drates from the diet is not always
effective. The review was
conducted by Dr. Dena
Bravata of the Stanford
University School of
Medicine in Palo
Alto, CA, and her
team of researchers
and was published
in the Journal of the
dietary studies published
between 1966 and 2003 to determine
how low-carbohydrate diets affected weight,
cholesterol, glucose, insulin levels and
blood pressure. The results indicated that
among obese patients, the amount of
weight loss was linked to compliance to the
diet, not how many carbohydrates were cut.
The research team also pointed out that
only five of the studies lasted longer than 90
days, so the long-term effects of restricting
carbohydrates is not well understood.
Most experts agree that these findings do
offer some insight into the effectiveness of
low-carbohydrate diets, but the jury is still
out. Many questions remain unanswered
and more research is needed before such
diets can be recommended for weight loss,
weight maintenance and overall health.
Bravata, Dena, M., et al. Efficacy and Safety of Low-
Carbohydrate Diets. Journal of the American Medical
Association. April 9, 2003. Vol. 289. No. 14. 1837-1850.
Foster, Gary, D., PhD., et. al. A Randomized Trial of a
Low-Carbohydrate Diet for Obesity. New England Journal
of Medicine. May 22, 2003. Vol. 348. No. 21. 2082-2090.
Samaha, Frederick, F., MD., et. al. A Low-Carbohydrate
Diet as Compared with a Low-Fat Diet in Severe Obesity.
New England Journal of Medicine. May 22, 2003. Vol.
348. No. 21. 2074-2081.
lthough high protein diets have been extremely popular, many health
experts have questioned their safety and efficacy. However, over the
past year, several studies have been published regarding
high protein diets, with some interesting results.
Researchers, led by Gary Foster, clinical
director of the Weight and Eating
Disorders Program at the University of
Pennsylvania School of Medicine,
evaluated high protein diets versus
other diet programs. In this first
study, researchers randomly
assigned obese men and women to
either the Atkins diet (low-carb) or a
low-calorie, high-carbohydrate diet.
After a six-month period, participants on
the Atkins diet lost 15 pounds, whereas
those on the more conventional diet lost seven
pounds. However, after one-year, both groups had kept
off approximately the same amount of weight.
In another study, researchers from the Philadelphia Veterans
Affairs Medical Center followed severely obese men and women on
either a low-carbohydrate diet similar to the Atkins plan, or a low-fat
plan. After six-months, the low-carbohydrate followers lost 13 pounds,
whereas the low-fat dieters lost four pounds. (Weight loss after one
year was not reported.) The findings of the two studies were published
in the New England Journal of Medicine.
Another study, which compared an American Heart Association
(AHA) type diet with a low-carbohydrate diet found that participants
were able to lose weight as well as lower their cholesterol levels on the
low-carbohydrate plan. The findings were presented at the AHA meet-
ing in November 2002. However, the AHA issued the following con-
cerns regarding the study:
The study evaluated a very small group with only 120 total partici-
pants -- only 60 consumed the high-fat, low-carbohydrate diet.
This was a short-term study over a period of just six months. The
conclusions from the study did not indicate that the weight loss
could be maintained over the long-term.
The conclusions from the study did not provide evidence over the
long-term that such a diet could be beneficial in improving long-
The diet was not conducted over a time period long enough to
evaluate the risk of heart disease. A diet high in saturated fat con-
tributes to heart disease.
A direct comparison (between dietary recommendations from
the AHA and the Atkins diet) was not studied.