Little Scientific Evidence Behind Most Weight-Loss Programs, Study Finds

— -- Just in time for swimsuit season, a new study has come out saying there's very little scientific evidence to prove most diet and weight-loss regimens actually help people lose weight and keep it off.

After reviewing more than 4,200 studies to evaluate various weight-loss programs -- from large, commercial programs to self-directed regimens -- researchers at Johns Hopkins University found that only a few dozen of these studies were "scientifically rigorous and reliable" and even fewer showed at least modest evidence of sustained weight loss over one year.

"I had hoped that more rigorous scientific studies of these programs had been done," said lead study author Dr. Kimberly Gudzune, assistant professor of medicine and weight loss specialist at the Johns Hopkins University School of Medicine.

Gudzune's review showed that there were at least some studies showing long-term evidence for weight loss, she and her team wrote in the study published today in the Annals of Internal Medicine.

Though many, if not all, weight-loss programs have their shortcomings, most of them have at least some benefit when compared to forgoing weight-loss regimens altogether, said Dr. David Katz, director of the Yale University Prevention Research Center.

"There is clearly some weight-loss benefit to a structured program as opposed to no program," said Katz, who was not involved in the study. "The larger commercial weight-loss programs have funded trials. Others that may be as good or better [than commercial programs] cannot afford [the research], so we tend to keep hearing about the same players again and again."

Although Gudzune pointed out that there wasn't enough substantial research to support most of these programs, she was pleased to learn that studies of these products, services and programs have increased over the last 10 years.

Gudzune said good research behind weight-loss programs is important because doctors recommend them to help patients lose weight.

"It's critical to understand whether these programs might be a good fit," she said. "I see them as an adjunct to the other care that I provide."

Doctor's Take

Though it may be true that there is very little data to support many of the weight-loss programs out there, it is important to remember that this does not mean that weight loss is a hopeless goal. The best thing you can do is to find what works for you, and follow through. Adopting a healthier lifestyle is a challenge -- but the right approach, combined with support from your doctor, family and friends, may help you drop those pounds -- and pick up the healthy benefits.

Dr. Taimur Khan is a medical resident embedded with the ABC News Medical Unit. Doctor's Take blogs explain the latest studies while offering residents' medical opinions.