Low Carb-, Low-Fat Diets Tied for Long-Term Weight Loss – Yahoo! News
MONDAY, Aug. 2 (HealthDay News) — If you're overweight, should
you cut carbs or fat?
A new two-year study suggests that it may not matter in the long run:
When combined with extensive guidance about eating and exercise, people
lost about the same amount of weight whether they were on an Atkins-style,
low-carbohydrate diet or a traditional low-fat diet.
“In general, dieters should be less concerned about what diet they're
on and more focused on finding strategies to stick to the diet they
chose,” advised study author Gary D. Foster, director of the Center for
Obesity Research & Education at Temple University.
There are some caveats, however. People in both groups only lost an
average of about 7 percent of their weight two years after beginning their
diet, although that added up because they were typically very
overweight.
And those who were on the low-carb diet did get one extra benefit:
Their blood pressure and levels of “good” cholesterol improved a bit more
than those who cut down on fat.
The study appears in the Aug. 3 issue of the Annals of Internal
Medicine.
There's long been research into which diet is the best. But this study
is unique because it looks at how diets work over the longer term, Foster
said.
In the study, funded by the U.S. National Institutes of Health,
researchers followed 307 overweight people for two years as they
participated in a low-carbohydrate diet — fashioned after the Atkins
diet — or a low-fat diet that was also low in calories.
Their average age was 45 and their average body-mass index was 36,
meaning they were typically obese, a step beyond simply being
overweight.
Those on the low-fat diet were told to eat 1,200-1,800 calories a day,
with fewer than 30 percent of them from fat. Those on the low-carb diet
were instructed to eat no more than 20 grams of carbs a day, although they
could eat all the fat and protein they wanted.
In addition to dieting, the participants received guidance about
dieting and exercise similar to that offered in commercial weight-loss
programs, Foster said.
On average, the participants — recruited in several cities across the
country — lost 7 percent of their weight after two years, or an average
of about just over 15 pounds. The results were similar, no matter which
diet they were on.
There was one difference, however. Foster said levels of “good”
cholesterol (the heart-healthy kind that you want) grew by about 11
percent in the low-fat group but more than twice that — about 23
percent — in the low-carb group. Blood pressure also fell by a greater
level in the low-carb group vs. the low-fat cohort.
It's not clear why the low-carb group might perform better in those
areas, Foster said, but the two differences are significant. Still, he
said, “we can't say following this diet or that diet will result in less
heart disease.”
Overall, he said, the message of the study is that the diets work about
equally well when it comes to weight loss.
Howard Sesso, assistant professor of medicine at Brigham and Women's
Hospital in Boston, said this suggests the kind of diet that a person
adopts may be less important than his or her ability to stick to it.
There's another message from the study, said Lona Sandon, assistant
professor of clinical nutrition at University of Texas Southwestern
Medical Center at Dallas. “It confirms what we have known for years: that
it's not fat versus carbohydrates. It's the calories that lead to weight
loss.”
But what of the fact that the participants lost a small percentage of
weight, on average? While a small weight loss can make a difference in
terms of risk factors for heart disease, “the study shows it is also
difficult to take weight off and keep it off long term, even when you have
good support,” she said. “These people represent what happens in real
life, not what we see on the 'Biggest Loser.' Losing weight and keeping it
off takes serious commitment. For most, their lifestyles and environments
just don't support that kind of commitment.”
More information
There's more on healthy weight loss at the U.S. National Library of Medicine.
