Nov. 14, 2006 (Chicago) -- Where's the beef? Just forget it -- and the chicken and fish, too.
Researchers have found that people who stuck to a vegetarian diet for at least one year lost more weight than those on a standard low-fat diet. And they shed considerably more excess flab than those who didn't stick with the meatless plan.
Additionally, levels of LDL "bad" cholesterol dropped after six months on the vegetarian diet, although they started to rebound when people went back to their normal eating habits a year later, says Lora A. Burke, PhD, professor of nursing and epidemiology at the University of Pittsburgh.
If you adhere to the vegetarian diet, "you will lose weight and have significant improvements in your heart disease risk profile," she tells WebMD.
Dairy Products, Eggs Allowed
Eighty were randomly assigned to follow a lacto-ovo-vegetarian diet, in which you can eat eggs and dairy products, but not red meat, poultry, or fish. The remaining 96 participants were assigned to a standard, low-calorie, low-fat diet.
People following the standard diet were told to get no more than 25% of their total calories from fat. Participants from both groups were told to count calories.
Additionally, women and men who weighed under 200 pounds were limited to 1,200 and 1,500 calories a day, respectively. Women who weighed more got a 1,500 calorie-a-day allowance, while heavier men were permitted 1,800 calories a day.
All the participants had regular weigh-ins and counseling sessions with a nurse practitioner for one year.
Veggie Diet Wins People Over
Burke says the researchers were concerned that people wouldn't stick to the veggie meal plan, but that did not prove to be the case -- at least during the year that structured counseling continued.
"Giving up meat is a huge, difficult change for Americans," she says. "One-third of participants didn't want to be on the vegetarian diet at the start of the study."
But many stuck it out. In fact, 40% were still meat-free 12 months later. In contrast, only 30% of people on the standard diet stayed on their diet plan for a year.
By 18 months out, people assigned to the lacto-ovo-vegetarian diet had lost an average of 11.2 pounds vs. 10.4 pounds in the standard-diet group.
Sticking to the Diet Is the Big Issue
The researchers then decided to look further at the people on the vegetarian diet, comparing those who stuck to the plan for at least one year with those who did not.
Among the findings:
- Those who adhered to the vegetarian meal plan lost an average of 16.5 pounds, compared with 4.8 pounds for those who didn't stick with it.
- Those who stuck it out also consumed fewer calories (1,452 vs.1,685 in the nonadherers), less fat (41 grams vs. 61 grams), and less saturated fat (13.4 grams vs. 20.8 grams).
- Six months in, LDL "bad' cholesterol levels in the adherent group improved significantly compared with the nonadherers.
Structured Visits Help People Stick It Out
Once structured counseling stopped at one year, people appeared to go back to their old ways, Burke says. Over the next six months, those who stuck with the diet for a year gained about 6 pounds. Weight remained stable among those who hadn't stuck with the diet to begin with.
That may explain why at 18 months, there was no significant difference in LDL cholesterol improvements among the two groups, she says.
"People on a structured diet plan need regular follow-up with a nutritionist, nurse practitioner or other health care professional," Burke says.
AHA spokesperson Gerald Fletcher, MD, a preventive cardiologist at the Mayo Clinic in Jacksonville, Fla., agrees.
"Losing weight and keeping it off is a lifelong problem, and people might have trouble sticking with this," he tells WebMD.
If you can't see a health care professional regularly, "you may want to set up computer reminders that ask you every five days or so whether you have weighed yourself and whether you're following your diet," Fletcher says. "These can be very effective."
Burke is now conducting a new two-year study in which participants have structured visits every six weeks to determine if the benefits of the vegetarian diet can be sustained further.