Is one diet better than the others?
Study finds 4 popular diets all work to lower weight, heart risk
Monday, November 10, 2003
ORLANDO, Florida (Reuters) — No matter what diet you are on, if you eat less and lose weight you also lower your risk of heart disease, doctors reported at an annual heart meeting.
Weight Watchers, the high-fat Atkins diet, the extremely low-fat Ornish diet and the high-protein, moderate carbohydrate Zone diet all help people lose weight and all reduce cholesterol, but in different ways, the researchers told a meeting of the American Heart Association this week.
“On average, participants in the study reduced their heart disease risk by 5 percent to 15 percent,” said Dr. Michael Dansinger of Tufts University in Boston.
“Instead of saying there is one clear winner here, we are saying they are all winners.”
And, as might be expected, the closer dieters followed the plans, the more weight they lost.
Those who stuck it out for a full year lost, on average, 5 percent of their body weight — or about 10 to 12 pounds.
While the dieters reduced heart disease “risk factors” such as cholesterol levels, overall blood pressure did not drop much and the study did not last long enough to see if this translated into a lower long-term risk of heart disease.
Instead, the researchers used statistics that show lowering cholesterol by a certain amount, for instance, reduces the risk of heart disease overall.
Dr. Robert Eckel of the University of Colorado, who heads the Heart Association’s nutrition committee, said the message is clear — lose weight however you can to reduce your risk of heart disease.
“I think weight reduction trumps a lot of other stuff,” Eckel said.
For the study Dansinger and colleagues chose 160 overweight people and randomly assigned 40 to each of four different diets. They weighed an average 220 pounds and needed to lose between 30 and 80 pounds.
All agreed to follow the diets to the best of their ability for two months, although none were enrolled in the full programs that Weight Watchers and Dr. Dean Ornish advocate.
They include exercise, group meetings and food diaries for Weight Watchers and stress reduction for the Ornish diet.
After two months, 22 percent of the dieters had given up. After a year, 35 percent dropped out of Weight Watchers and the Zone diets and 50 percent had quit the Atkins and Ornish plans.
Dansinger and other researchers said the study suggested there is no one-size-fits-all diet best for everyone.
“The type of person who is going to go for a low-fat, vegetarian diet is not, in my experience, the kind of person who is going to go for a high-meat diet,” Dansinger said.
But for people with high cholesterol levels, the Ornish diet might be the most beneficial, Dansinger said.
“The Ornish diet, low-fat vegetarian, was best for lowering the bad LDL cholesterol, while other diets were better at raising the good HDL cholesterol,” Dansinger said. Low density lipoprotein cholesterol is the stuff that clogs arteries, while high density lipoprotein carries fat out of the blood.
“Atkins reduced LDL 8.6 percent, Zone 6.7 percent, Weight Watchers 7.7 percent and Ornish 16.7 percent,” Dansinger said in a statement afterwards. He said the Atkins and Zone diets diet raised HDL by about 15 percent, Weight Watchers by 18.5 percent, and Ornish by 2.2 percent.
Ornish said doctors often place too high a value on high HDL levels. “If you reduce fat, there is less garbage, less saturated fat and cholesterol, so your body needs less garbage trucks,” he said.
But Dansinger said his study was one of several that has suggested the high-fat Atkins diet, in the short-term, does not raise the risk of heart disease.