By ALICIA CHANG, AP Science Writer – Thu Feb 26, 4:15 AM PST

Debbie Mayer, who was part of the clinical trial, poses at her home in Brockton, Mass. Tuesday, Feb. 24, 2009. Low-fat or low-carb, as long as your diet lowers calories and you stick with it, you can lose weight, finds a federal study that followed people for two years – one of the longest such comparisons. (AP Photo/Lisa Poole)
LOS ANGELES – Low-fat, low-carb or high-protein? The kind of diet doesn’t matter, scientists say. All that really counts is cutting calories and sticking with it, according to a federal study that followed people for two years. However, participants had trouble staying with a single approach that long and the weight loss was modest for most.
As the world grapples with rising obesity, millions have turned to popular diets like Atkins, Zone and Ornish that tout the benefits of one nutrient over another.
Some previous studies have found that low carbohydrate diets like Atkins work better than a traditional low-fat diet. But the new research found that the key to losing weight boiled down to a basic rule — calories in, calories out.
“The hidden secret is it doesn’t matter if you focus on low-fat or low-carb,” said Dr. Elizabeth Nabel, director of the National Heart, Lung and Blood Institute, which funded the research.
Limiting the calories you consume and burning off more calories with exercise is key, she said.
The study, which appears in Thursday’s New England Journal of Medicine, was led by Harvard School of Public Health and Pennington Biomedical Research Center in Louisiana.
Researchers randomly assigned 811 overweight adults to one of four diets, each of which contained different levels of fat, protein and carbohydrates.
Though the diets were twists on commercial plans, the study did not directly compare popular diets. The four diets contained healthy fats, were high in whole grains, fruits and vegetables and were low in cholesterol.
Nearly two-thirds of the participants were women. Each dieter was encouraged to slash 750 calories a day from their diet, exercise 90 minutes a week, keep an online food diary and meet regularly with diet counselors to chart their progress.
There was no winner among the different diets; reduction in weight and waist size were similar in all groups.
People lost 13 pounds on average at six months, but all groups saw their weight creep back up after a year. At two years, the average weight loss was about 9 pounds while waistlines shrank an average of 2 inches. Only 15 percent of dieters achieved a weight-loss reduction of 10 percent or more of their starting weight.
Dieters who got regular counseling saw better results. Those who attended most meetings shed more pounds than those who did not — 22 pounds compared with the average 9 pound loss.
Lead researcher Dr. Frank Sacks of Harvard said a restricted calorie diet gives people greater food choices, making the diet less monotonous.
“They just need to focus on how much they’re eating,” he said.
Sacks said the trick is finding a healthy diet that is tasty and that people will stick with over time.
Before Debbie Mayer, 52, enrolled in the study, she was a “stress eater” who would snack all day and had no sense of portion control. Mayer used to run marathons in her 30s, but health problems prevented her from doing much exercise in recent years.
Mayer tinkered with different diets — Weight Watchers, Atkins, South Beach — with little success.
“I’ve been battling my weight all my life. I just needed more structure,” said Mayer, of Brockton, Mass., who works with the elderly.
Mayer was assigned to a low-fat, high-protein diet with 1,400 calories a day. She started measuring her food and went back to the gym. The 5-foot Mayer started at 179 pounds and dropped 50 pounds to 129 pounds by the end of the study. She now weighs 132 and wants to shed a few more pounds.
Another study volunteer, Rudy Termini, a 69-year-old retiree from Cambridge, Mass., credits keeping a food diary for his 22-pound success. Termini said before participating in the study he would wolf down 2,500 calories a day. But sticking to an 1,800-calorie high-fat, average protein diet meant no longer eating an entire T-bone steak for dinner. Instead, he now eats only a 4-ounce steak.
“I was just oblivious to how many calories I was having,” said the 5-foot-11-inch Termini, who dropped from 195 to 173 pounds. “I really used to just eat everything and anything in sight.”
Dr. David Katz of the Yale Prevention Research Center and author of several weight control books, said the results should not be viewed as an endorsement of fad diets that promote one nutrient over another.
The study compared high quality, heart healthy diets and “not the gimmicky popular versions,” said Katz, who had no role in the study. Some popular low-carb diets tend to be low in fiber and have a relatively high intake of saturated fat, he said.
Other experts were bothered that the dieters couldn’t keep the weight off even with close monitoring and a support system.
“Even these highly motivated, intelligent participants who were coached by expert professionals could not achieve the weight losses needed to reverse the obesity epidemic,” Martijn Katan of Amsterdam’s Free University wrote in an accompanying editorial.
Cutting calories key to weight loss: study
Overweight patients cast a shadow at a weight reduction clinic. A new study has found that eating heart-healthy, low-calorie foods and exercising is the key to losing weight regardless of levels of protein, fat or carbohydrates.(AFP/File/Frederic J. Brown)
The research, funded by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health, seems to argue against blanket use of diets that do not necessarily limit calories but call for eating certain foods such as vegetables or proteins, at the expense of others.
The NIH study of 811 volunteers, 38 percent of them men and 62 percent women, aged 30-70 and either overweight or obese, looked at diets that have been popular in the United States in recent years, even as the number of obese Americans has soared.
The “Preventing Overweight Using Novel Dietary Strategies (POUNDS LOST) study found similar weight loss after six months and two years among participants assigned to four diets that differed in their proportions of these three major nutrients,” said researchers.
“The diets were low or high in total fat (20 or 40 percent of calories) with average or high protein (15 or 25 percent of calories). Carbohydrate content ranged from 35 to 65 percent of calories.
“The diets all used the same calorie reduction goals and were heart-healthy low in saturated fat and cholesterol while high in dietary fibre,” said researchers, whose study is published Thursday in the New England Journal of Medicine.
Participants lost an average 13 pounds (5.9 kilos) at six months and maintained a nine-pound (four-kilo) loss at two years.
“These results show that, as long as people follow a heart-healthy, reduced-calorie diet, there is more than one nutritional approach to achieving and maintaining a healthy weight,” said Dr. Elizabeth Nabel, director at NHLBI.
“This provides people who need to lose weight with the flexibility to choose an approach that they’re most likely to sustain: one that is most suited to their personal preferences and health needs,” she stressed.
Sixty-six percent of US adults are overweight and of those, 32 percent are obese, Centers for Disease Control and Prevention data show.
By AFP – Thu Feb 26, 8:42 AM PST