If patients know about their genetic information, they are likely to make some lifestyle changes to avoid being obese or getting diabetes.

In a study by David Kaufman of the Genetics and Public Policy Center in Washington DC, nearly 60 percent of 1048 people whose genome scans were conducted changed their lifestyle after they were told about future risks based on their gene profile. Interestingly, it is increasingly difficult to convince people to improve their lifestyle, despite them knowing that family history shows high risk chances of type 2 diabetes and heart attacks.

David Kaufman of the Genetics and Public Policy Center in Washington DC quizzed 1048 customers who had ordered genome scans from Decode Genetics of Reykjavik, Iceland, 23andMe of Mountain View, California, or Navigenics, based in Foster City, California.

"I was surprised at the number of people who said they'd made changes already," said Kaufman, who revealed the results this week at the annual meeting of the American Society of Human Genetics (ASHG) in Washington DC.

A third of the patients were being more careful about their diet, 14 per cent were exercising more and 16 per cent of those changed their medication.“The question is how long it is sustained," said David Marrero, a specialist in diabetes prevention at Indiana University in Indianapolis, even as he is impressed by reported changes in behavior among people who did their gene scans.

"They tend to be people who are highly motivated health-seekers and science geeks," says Barbara Bernhardt of the University of Pennsylvania in Philadelphia, who has conducted detailed interviews with 60 volunteers in the Coriell Personalized Medicine Collaborative, a pioneering effort to study the medical value of genetic information.