ARE
LOW-CARB DIETS FOR REAL?
If you are interested in losing weight,
chances are you’ve heard about low-carb diets.
Low-carb (or low carbohydrate) diets are
all the rage these days. Housewives and young professionals have
heard about it, tried it, and passed on the message. The food
industry has jumped onto the bandwagon by putting out new lines
of low-carb foods. Advertising is working overtime to sell the
idea.
Well, low-carb diets are in the hot seat,
reported the US press recently.
While the South Beach Diet and the Atkins
Diet continue to tally book sales – a staggering estimated 30
million to date – no less than 11 health organizations have
teamed up to dispel what they call popular misconceptions about
the low-carbohydrate approach, and to warn about the substantial
risk of its long-term use.
The Partnership for Essential Nutrition,
led by former U.S. Surgeon General C. Everett Koop's Shape Up
America! group, cautions that studies show the low-carb
approach can starve the brain of carbohydrates, produce
constipation and other gastrointestinal problems, reduce energy
levels and cause difficulty concentrating.
In the long run, the groups warn, the
regimens can stress the kidneys and increase the risk of liver
disorders, gout, coronary heart disease, diabetes, stroke and
several types of cancer. Going low on carbs (or eliminating
carbs altogether) means you load up on proteins and fats.
Neither is particularly good for your health.
"Low-carbohydrate diets conflict with
decades of solid scientific research that clearly encourages us
to reduce saturated fat and boost fruit, vegetable and fiber
intake," said Barbara Moore, president and CEO of Shape Up
America!
These diets have "promoted the simplistic
belief that individuals can solve their weight and related
health problems by eliminating one nutrient from the diet, or at
least drastically reducing intake of that nutrient:
carbohydrates," noted Alison Rein, assistant director of food
and health policy for the National Consumers League, one of the
groups in the partnership. It is telling that the partnership
received a $25,000 grant from Weight Watchers to produce
a public service announcement for TV about the potential dangers
of low-carb diets.
Not only is this "magic bullet" approach
wrong, Rein said, but "it has also likely led to decreased
consumption of fresh fruit and vegetables, whole grains, low-fat
dairy foods and fiber."
Colette Heimowitz, director of education
and research for Atkins Nutritionals, dismissed those concerns,
saying that research "continues to support the safety of low-carb
diets as an option for weight loss and maintenance." She said
that Atkins Nutritionals has created a food ladder to help guide
consumers to add back carbohydrates after the induction phase of
the Atkins diet, when carbs are most strictly limited. The
partnership, Heimowitz countered, "is funded by big industry and
Weight Watchers. They have millions of dollars behind
them. . . . These are the companies whose sales are plummeting
and who are also launching their own low-carb products."
Moore said 10 of the 11 health groups in
the partnership have contributed only time, not money. Nine are
nonprofit, including one that is funded by the federal Centers
for Disease Control and Prevention. Two are university
affiliated. Shape Up is footing the bill for the
partnership. The partnership also includes the Alliance for
Aging Research, the American Association of Diabetes Educators,
the American Institute for Cancer Research, the American Obesity
Association, the National Women's Health Resource Center, the
Pennington Biomedical Research Center in Baton Rouge, La., the
Society for Women's Health Research, the University of
California-Davis Department of Nutrition and the Yale-Griffin
Prevention Research Center in Derby, Conn.
The partnership offers this advice to those
considering a low-carb approach to weight loss:
Beware quick
weight loss Studies show that the fast, initial drop
in pounds that occurs with extremely low-carb diets such as
Atkins is mostly due to water loss caused by a metabolic
condition called ketosis. "This form of weight loss is extremely
stressful on the body and forces the brain to alter its
metabolism," Moore said. "And it can't be ameloriated by
drinking more water." And as the partnership noted, "research
has shown that this weight loss cannot be sustained over time."
"We agree with that," said cardiologist
Arthur Agatston, author of the South Beach Diet, which doesn't
push its adherents into ketosis. "Even in advertising, we have
asked the publisher not to make claims about rapid weight loss.
We emphasize again and again slow weight loss, about one to two
pounds per week, which is more-permanent weight loss."
Calories count.
"The Atkins Essentials" says poultry, fish, shellfish, meat and
eggs are foods that "you do not need to limit." It notes that
exceptions are processed meats, such as bacon and hot dogs, that
may be cured with sugar or contain fillers that contribute carbs.
The partnership noted that "a surprising
number" of Americans are less concerned about the amount they
eat than what foods they consume. "Contributing to this view is
the growing belief [among those polled] that low-carb diets
create weight loss without cutting calories, a view that the
overwhelming number of credible scientific studies refutes." For
example, a 2003 review article published in the Journal of
the American Medical Association found that weight loss on
low-carb diets is due to decreased calories. On the first two
weeks of South Beach Diet, adherents are advised to eat specific
menus that range from about 1,100 to 1,500 calories per day --
similar to traditional low-calorie diets.
"The monotony of the diets is a major
factor in why people lose weight, because they end up being
bored and eating less," the partnership noted.
Representatives for Atkins Nutritionals
agree that their adherents consume fewer calories, but say it's
because the combination of higher fat and protein is more
satisfying to dieters.
"We have already demonstrated in studies
that people end up eating fewer calories on Atkins," Heimowitz
said. "They're eating about 1,400 to 1,800 calories per day is
what studies have demonstrated" -- roughly what people are
advised to eat on traditional weight-loss regimens.
On South Beach, "calories count, but
counting calories doesn't work," Agatston said -- the reason
that the program advises consuming healthy food in limited
portions.
Eat healthy carbs.
A national opinion poll conducted for the partnership in June
found a lack of even "a rudimentary understanding of what carbs
are and their role in the diet." The National Academy of
Sciences recommends that Americans eat a minimum of 130 grams of
carbohydrates per day -- roughly six times what is included in
the induction phases of low-carb diets. The academy also noted,
however, that most Americans eat two to three times more than
they need. So reducing processed carbs makes sense for many
people seeking to control their weight as well as for those
aiming to choose better carbs: Highly processed carbohydrates,
such as those found in sugary or white-flour baked goods are
more likely to raise blood sugar and boost production of
insulin.
Expect snap-back
pounds. Research shows that as carbohydrates are
reintroduced, rapid weight gain often occurs for low-carb
dieters, the partnership noted.
"That's true, if you go into ketosis, "
Agatston said. By eating too few carbohydrates, stores of
glycogen are depleted. Eat carbs again "and you will snap back
weight," Agatston said. "We don't find that [with South Beach]
because we don't put people into ketosis."
In "Atkins Essentials," readers are warned
that "the first week on Atkins may not be, punning aside, a
piece of cake." At the end of the second week, the book guides
readers toward deciding whether to stay in this first phase or
to move on to one of the other three phases of the diet, which
gradually reintroduces more carbohydrates, such as berries and
whole grains, to guide dieters gradually out of ketosis.
Choose
high-protein foods wisely. South Beach emphasizes
fish, poultry and other protein low in saturated fat. But a
survey conducted for the partnership found that half of those on
low-carb diets are increasing consumption of steak and 30
percent are eating more bacon, which tend to be high in
saturated fat. People on low-carb regimens are "eating more eggs
and less cereal, fruit and dairy," Moore noted.
Read ingredients
carefully. The average low-carb dieter spends about
$85 a month on any number of the more than 1,000 products
labeled low-carb, carb-smart, carb-aware, carb-wise or reduced-carb,
or otherwise claiming to be carb-restricted. Yet there is no
official or uniform definition of these terms, leaving food and
beverage manufacturers free to apply their own. "While these
foods are widely advertised and promoted, many of these claims
are not regulated by the federal government, leading to
confusion over what these labels mean," the partnership said,
noting that consumers need to compare products carefully. |