FRIDAY, Oct. 5 (HealthDay News) -- Not all diet plans are equally heart-healthy, according to a study ranking eight popular weight-loss programs.
Diets that emphasize a variety of fruits and vegetables scored better than those with a heavy protein focus.
The Ornish diet plan came out on top with the most potential to prevent heart disease risk factors. The Atkins diet came in last, lagging behind the Zone and Weight Watchers.
"It was not surprising to me that the Ornish diet came out on top given that the index used is designed to measure dietary components related to risk of heart disease," said dietician Lona Sandon, a national spokeswoman for the American Dietetic Association.
Sandon said the take-home message for consumers is "if heart disease is your concern, you need to focus more on fruits, vegetables and make all your grains whole grains, as well as limit intake of animal foods and fats."
The findings are published in the October issue of the Journal of the American Dietetic Association.
Researchers at the University of Massachusetts Medical School ranked daily meal plans and food recommendations in the Ornish Plan, the Zone Diet, Atkins, two Weight Watchers plans, the South Beach Diet, the New Glucose Revolution and the 2005 MyPyramid plan.
The rankings were based on the Alternate Healthy Eating Index (AHEI), which uses the daily dietary intake of fruits, vegetables, fats, fiber, nuts, soy and white meats instead of red meat to determine how much benefit a diet has for heart health.
The highest possible score is 70. While none of the diets had a perfect score, they varied across a 20-point spread:
Study author and clinical psychologist Sherry Pagoto said there's no cut-off point in the AHEI scale below which a diet could be definitively considered heart unhealthy. But other studies have ranked low-quality diets in populations at risk for heart disease around the 30-point mark.
"We were most surprised by the fact that the MyPyramid wasn't even in the top three. We figured that this would be a model diet because it is based on the U.S. Department of Agriculture dietary recommendations," Pagoto said.
However, coming in last doesn't mean a diet is of low quality, she said. All of the diets have the potential to be healthy and have been shown in a variety of studies to result in weight loss, which is itself important to improving heart health. Additionally, coming in first does not mean the diet plan is ideal for everyone, she added.
"While the Ornish plan was on top, it's a hard one for most people to follow," Pagoto said. The Ornish plan is a very low-fat, low-calorie, primarily vegetarian diet developed for people who have survived heart attacks, she explained.
In her work counseling clients at the University of Massachusetts Memorial Weight Center, Pagoto said she has learned that it's important for people to be able to stick to the diet plan they choose.
"There is more than one element of a diet to consider," she said.