October 14, 2003
The following article is from the Vancouver Sun.
Low-carb dieters can eat more calories
and still lose weight
Surprising result supports long-disparaged claims of diet-guru Dr.
Daniel Haney Associated Press
FORT LAUDERDALE, Fla. -- The dietary establishment has
long argued it's impossible, but a new study offers intriguing evidence
for the idea that people on low-carbohydrate diets can actually eat more
than folks on standard low-fat plans and still lose weight.
Perhaps no idea is more controversial in the diet world
than the contention -- long espoused by the late Dr. Robert Atkins -- that
people on low-carbohydrate diets can consume more calories without paying
a price on the scales.
Over the past year, several small studies have shown, to
many experts' surprise, that the Atkins approach actually does work
better, at least in the short run. Dieters lose more than those on a
standard American Heart Association plan without driving up their
cholesterol levels, as many feared would happen.
Skeptics contend, however, that these dieters simply
must be eating less. Maybe the low-carb diets are more satisfying, so they
do not get so hungry. Or perhaps the food choices are just so limited that
low-carb dieters are too bored to eat a lot.
Now, a small but carefully controlled study offers a
strong hint that maybe Atkins was right: People on low-carb, high-fat
diets can eat more.
The study, directed by Penelope Greene of the Harvard
School of Public Health and presented at a meeting here this week of the
American Association for the Study of Obesity, found that people eating an
extra 300 calories a day on a very low-carb regimen lost just as much
during a 12-week study as those on a standard low-fat diet.
Over the course of the study, they consumed an extra
25,000 calories. That should have added up to about 3.2 kilograms (seven
pounds). But for some reason, it did not.
"There does indeed seem to be something about a low-carb
diet that says you can eat more calories and lose a similar amount of
weight," Greene said.
That strikes at one of the most revered beliefs in
nutrition: A calorie is a calorie is a calorie. It does not matter whether
they come from bacon or mashed potatoes; they all go on the waistline in
just the same way.
Not even Greene says this settles the case, but some at
the meeting found her report fascinating.
"A lot of our assumptions about a calorie is a calorie
are being challenged," said Marlene Schwartz of Yale. "As scientists, we
need to be open-minded."
Others, though, found the data hard to swallow.
"It doesn't make sense, does it?" said Barbara Rolls of
Pennsylvania State University. "It violates the laws of thermodynamics. No
one has ever found any miraculous metabolic effects."
In the study, 21 overweight volunteers were divided into
three categories: Two groups were randomly assigned to either low-fat or
low-carb diets with 1,500 calories for women and 1,800 for men; a third
group was also low-carb but got an extra 300 calories a day.
The study was unique because all the food was prepared
at an upscale Italian restaurant in Cambridge, Mass., so researchers knew
exactly what they ate. Most earlier studies simply sent people home with
diet plans to follow as best they could.
Each afternoon, the volunteers picked up that evening's
dinner, a bedtime snack and the next day's breakfast and lunch. Instead of
lots of red meat and saturated fat, which many find disturbing about low-carb
diets, these people ate mostly fish, chicken, salads, vegetables and
"This is not what people think of when they think about
an Atkins diet," Greene said. Nevertheless, the Atkins organization agreed
to pay for the research, though it had no input into the study's design,
conduct or analysis.
Everyone's food looked similar but was cooked to
different recipes. The low-carb meals were five-per-cent carbohydrate,
15-per-cent protein and 65-per-cent fat. The rest got 55-per-cent
carbohydrate, 15-per-cent protein and 30-per-cent fat.
In the end, everyone lost weight. Those on the
lower-cal, low-carb regimen took off 10.4 kilograms (23 pounds), while
people who got the same calories on the low-fat approach lost 7.7
kilograms (17 pounds). The big surprise, though, was that volunteers
getting the extra 300 calories a day of low-carb food lost nine kilograms
"It's very intriguing, but it raises more questions than
it answers," said Gary Foster of the University of Pennsylvania. "There is
lots of data to suggest this shouldn't be true."
Greene said she can only guess why the people getting
the extra calories did so well. Maybe they burned up more calories
digesting their food.
Dr. Samuel Klein of Washington University, the obesity
organization's president, called the results "hard to believe" and said
perhaps the people eating more calories also got more exercise or they
were less apt to cheat because they were less hungry.
© Copyright 2003 Vancouver Sun