She recommends following the Mediterranean diet for heart disease prevention, however, because it’s easier for most people to stick with permanently.
Researchers have also found health benefits such as reversal of hypertension from the Dietary Approaches to Stop Hypertension (DASH) diet. It includes about 20 to 35 percent of calories from fat — somewhat less than the 30 to 40 percent of calories allowed on the Mediterranean diet plan and more than what’s allowed on the Ornish plan. The DASH plan has the same emphasis on fruits, vegetables, and whole grains but limits sodium intake and alcohol and emphasizes potassium-rich foods such as bananas. It also includes plenty of animal protein such as lean beef, low-fat dairy, and chicken, so it might be easier for some people to follow.
What type of professional support will you get?
People who participate in clinical trials testing specific diets nearly always get help from dietitians and sometimes even get free food delivered — a far cry from the real world.
Ornish said that people who are most successful at adopting his plan long-term usually require 72 hours of training with an exercise physiologist and registered dietitian. Medicare now offers coverage for these educational sessions for heart disease patients, usually reimbursing about 80 percent of the $80 per hour cost.
The Mediterranean diet may take less time to learn, but still may require a few hours of counseling from a dietitian, said McManus. Medicare and many other insurance plans cover professional counseling four times a year for those with type 1 and type 2 diabetes. Those who are obese with a body mass index of 30 or greater can also get coverage under a mandate in the federal health law.
“It takes a while to adapt depending on a person’s baseline diet,” McManus said. “Someone may need to switch from butter to olive oil and move from an animal-based meal to a more plant-based one that includes very small amounts of chicken or lean meat.”
How willing are you to make big changes?
Both the Ornish and Mediterranean diets require significant makeovers if you’re following a typical American-style diet, but the Mediterranean diet is likely closer to what you’re already eating now.
“I never feel like I’m depriving myself,” said Abby Sloane, 27, who switched to the Mediterranean diet five years ago and dropped 90 pounds, which she’s kept off. She said it wasn’t too difficult to switch from nachos and chips to whole grains and hummus after finding recipes on the website from the Boston-based nutrition education organization Oldways, where she now works.
“It’s not really a diet; it’s a lifestyle change,” Sloane said. “I didn’t want something that I tried for a few months. I wanted to change my life.”