Two studies of the popular diets that limit sugar and processed starches show
they can work faster than some low-fat diets.
Both studies published in the Annals of Internal Medicine showed that after
six months, the low-carb dieters lost more weight than the low-fat group. And
one study showed that after 12 months, both groups had lost about the same
amount of weight.
In one study, a team at the Veterans Affairs Medical Center in Philadelphia
followed 132 obese adults who were assigned randomly either to a
low-carbohydrate diet with intake of less than 30 grams of carbs a day, or a
low-calorie diet that kept fat intake at a moderate 30 percent of calories from
fat.
Volunteers with diabetes had better control of blood sugar on the low-carb
diet, the researchers reported.
The low-carb group lost weight faster, but the low-fat dieters caught up.
A year later, both groups had lost about the same amount of weight -- 11 to
19 pounds for the low-carb group and 7 to 19 pounds for the low-fat group.
Dr. Linda Stern, who led the study, said it confirmed that any diet that cuts
calories will work.
"Americans are overweight because we're eating too much food and ingesting
too many calories," she said in a statement.
But most people tend to overindulge in high-carbohydrate foods. "I think a
low-carbohydrate diet is a good choice because much of our overeating has to do
with consumption of too many carbohydrates," she added.
In the second study, a team from Duke University followed 120 overweight
people and found those on the low-carb diet who also took a variety of vitamins
and supplements lost an average of 26 pounds, compared to an average of 14
pounds on a low-fat diet after six months.
However, the low-fat dieters lowered their cholesterol levels more, reducing
their risk of heart disease.
"We can no longer dismiss very-low-carbohydrate diets," Dr. Walter Willett of
the Harvard School of Public Health wrote in a commentary. But researchers said
more study was needed to show whether low-carb diets are safe in the long term.
"Patients should focus on finding ways to eat that they can maintain
indefinitely rather than seeking diets that promote rapid weight loss," Willet
added.
