Overweight and obese research participants lost the same amount of weight and were similarly dedicated to a diabetes-prevention program whether they learned their genes put them at high or low risk - or when they hadn't been counseled at all.

"It's very, very hard to change behavior," said lead researcher Dr. Richard Grant, now at Kaiser Permanente Northern California in Oakland.

"The idea that a number, whether it's a genetic number or anything, will have a big impact on changing people's behavior - it just won't work."

Researchers have predicted that people who learn they are at extra-high risk of diabetes might be more motivated to change their lifestyle, and patient surveys support that idea.

But there is also the concern that those at low genetic risk will get a false sense of reassurance and believe that eating a healthy diet and exercising aren't important for them.

To examine those theories, Grant and his colleagues tested middle-aged adults at Massachusetts General Hospital in Boston for 36 genetic markers known to be linked to type 2 diabetes. Forty-two people with the highest genetic risk and 32 with the lowest risk then went to a brief counseling session about those findings.

After counseling, the researchers started people on both ends of the risk spectrum on a 12-week group diet and exercise education program, along with another 34 people who had never had their genes tested.

Over the course of the program, participants lost an average of 8.5 pounds, and just under one-third of them lost at least five percent of their initial body weight. There was no difference in weight loss among people with high or low genetic risk - nor was there a difference in participants' motivation to prevent diabetes or how closely they stuck to the program schedule.

"Even though people have the intent and they think genetic information will have an impact, when you actually look at their behavior to reduce their risk of diabetes we didn't see any differences," Grant told Reuters Health.

Researchers noted that current genetic tests still have only a limited ability to predict who will end up getting diabetes or other preventable diseases.

In the new study, participants at high genetic risk had an approximately 17-percent chance of getting diabetes in the next three years, compared to a nine-percent chance for the lowest-risk group, the researchers reported in Diabetes Care.

It's not clear, they said, whether having a more accurate predictor would provide a greater incentive for high-risk people to change their lifestyle.

"We've really been talking about genetic information that doesn't change your risk very much in either direction," said Saskia Sanderson, a genetics and health behavior researcher from the Mount Sinai School of Medicine in New York.

"Before we jump to the conclusion that genetic information is never going to motivate people to change their lifestyles, we have to be very aware that this type of research is still in the early stages," Sanderson, who wasn't involved in the new study, told Reuters Health.

"Although this study suggests that at the moment genetic information doesn't motivate behavior change, that's not to say it won't in the future."

For now, Grant said, expensive genetic tests to determine people's risk for lifestyle diseases might not be worth it until the tests are more predictive or doctors can recognize which patients are most likely to be motivated by their results.

SOURCE: bit.ly/Qsw78I Diabetes Care, online August 28, 2012.

• A Permanent Economic Emergency