Surprise! Eating a healthy diet and regularly exercising helps obese Americans lose more weight than those who turn to diet fads and pills.

Researchers from Beth Israel Deaconess Medical Center and Harvard Medical Center analyzed data from the National Health and Nutrition Examination Survey, which was conducted by the CDC. The data came from more than 4,000 obese individuals aged 20 years and older with a BMI of 30 or over.

More than half of the people in the survey reportedly were trying to lose weight at the time of the study, which was conducted between 2001 and 2006. About 40 percent had lost 5 percent or more of their body fat in that time, and 20 percent of the participants lost 10 percent or more.

They found that the people who were most successful in losing weight exercised more and ate less fat than those who did not. Those who joined weight-loss programs appeared to have the most success and patients who received prescription weight loss medication also saw success.

On the other hand, those who reported going on liquid diets, nonprescription weight loss pills and eating diet foods and products did not see a successful weight loss.

"Obese Americans who see a 5 to 10 percent weight loss are already going to see health benefits and effects on diabetes, hypertension and coronary heart disease," said lead author of the study, Dr. Jacinda M. Nicklas, a clinical research fellow at Beth Israel Deaconess Medical Center and Harvard Medical School. "These are the sort of things that are tried and true."

Nicklas said the study results are particularly relevant since more than one-third of American adults are obese, according to the CDC, and 17 percent of children and teens are obese.

Weight loss programs give people accountability because it is something they have invested in themselves, Nicklas said.  While the fads and supplements and low-fat foods have created a large market for themselves, the authors said it's encouraging that the most successful ways of losing weight are accessible and affordable.

"This study, though observational in design, supports weight loss through proper eating and activity - a fact that is often challenged in today's quick-fix world," said Connie Diekman, director of university nutrition at Washington University in St. Louis.

"Diet and exercise are reflecting a commitment," said Keith Ayoob, associate professor of pediatrics at Albert Einstein College of Medicine in the Bronx. "Without a commitment, there will be no success. With commitment to gradual changes, you keep your eye on the bigger picture and are able to accept that quick fixes are never the answer."

And while the study suggests that prescription medication can be helpful, there are costs, noted Dr. David Katz, director of the Yale Prevention Center.  While the findings may be obvious to some, it should be a "reality check" to others.

"Costs in both dollars and side effects that better use of feet and forks do not impose," said Katz. "And while you are unlikely to share your prescription with all the members of your family, healthier habits only get stronger when shared. "

Hope springs eternal for weight loss by magical, effortless means, continued Katz.

"It is helpful to know that in the real world, magic doesn't work, but figuring out how to eat better and exercise more does," he said.  "It's a reminder regarding the lustrous promises about weight loss that abound, that all that glitters is not gold."