Low-Carb
Diet Reduced Weight by 10%
Patients'
blood lipid profiles improved, even though there was much more fat in
the diet.
At
six months, a low-carbohydrate diet resulted in 10% reduction in body
weight and significant improvement in lipid profile, as described in
the July issue of the American Journal of Medicine.
"While
we're impressed with the weight loss of this diet, we still are not
sure about the safety of it," lead author Eric C. Westman, MD,
MHS, of Duke University in Durham, North Carolina, says in a news
release. "More studies need to be done in order to be confident
about the long-term safety of this type of diet."
Westman's
group placed 51 overweight or obese healthy volunteers who wanted to
lose weight on a very low carbohydrate diet (<25 g/d) with no limit
on caloric intake. Subjects also received nutritional supplementation,
recommendations about exercise, and participation in group meetings.
Subjects
"could eat an unlimited amount of meat and eggs, as well as two
cups of salad and one cup of low-carbohydrate vegetables such as
broccoli and cauliflower a day," Westman says.
In
41 subjects (80%) who attended visits through six months, mean (±SD)
body weight decreased 10.3%±5.9% (P<.001) from baseline to
six months. This equalled a reduction in body weight of 9.0±5.3 kg
and body mass index of 3.2±1.9 kg/m2. Mean percentage of
body weight that was fat decreased 2.9%±3.2% from baseline over six
months (P<.001).
Serum
total cholesterol level decreased 11±26 mg/dL (P=.006),
low-density lipoprotein cholesterol level decreased 10±25 mg/dL (P=.01),
triglyceride level decreased 56±45 mg/dL (P<.001),
high-density lipoprotein (HDL) cholesterol level increased 10±8 mg/dL
(P<.001), and the cholesterol/HDL cholesterol ratio
decreased 0.9±0.6 units (P<.001).
"We
were somewhat surprised to find that patients' blood lipid profiles
improved, even though there was much more fat in the diet,"
Westman says. "We had thought the fat in the diet would increase
the cholesterol."
The
mean serum bicarbonate level decreased 2±2.4 mmol/L (P<.001)
and blood urea nitrogen level increased 2±4 mg/dL (P<.001).
All participants developed ketonuria at a level comparable to that of
a nondieting person fasting for two days, according to Westman.
"This
is a finding that we need to learn more about," he says.
"The level of ketones present was not terribly high, but we don't
know if this is safe or harmful to one's health over a long period of
time."
Although
this study lasted longer and had more participants than prior studies,
limitations include uncontrolled design, dropout of 20% of subjects,
and enrollment of only healthy volunteers, warranting caution in
generalizing to people with illness.
"If
someone has a medical problem or is taking medications, they should
only do this diet under the supervision of a health care
provider," Westman says. Am
J Med. 2002;113:30-36
FACT
Pravastatin
Curbs Proteinuria in Hypertensives
In
the July issue of Hypertension they reported that treatment with
pravastatin prompts a significant reduction in proteinuria in
normolipidemic patients with well-controlled hypertension.
