Weight loss surgery has always been considered a drastic option for weight loss — doctors nearly always recommend other weight loss strategies. Surgery is a last-ditch effort, when for medical reasons it is necessary to lose many extra pounds in a shortened period of time. But it is extremely effective, and some people who cannot lose weight in any other way find surgery to be a life-saver.

Now, a group of Swedish researchers say they have stumbled across evidence of positive changes in gene-expression among patients who underwent a gastric bypass surgery. In other words, weight loss surgery may change your genes for the better, enabling you to continue to maintain a healthy weight.

The group's research dealt with epigenetics, chemical modifications imposed externally on genes by lifestyle or environmental influences, of the skeletal muscles in eight obese women, scheduled to undergo gastric bypass surgery, and 16 women of normal weight, Fox News reported. Gastric bypass surgery entails a surgical change to the digestive system by shrinking the stomach and rearranging the intestines. Most surgeons say it's the least risky form of weight loss surgery.

Researchers hope the results of their study will be helpful in producing weight loss medication that assimilates this alteration in gene expression.

At the root of this gene alteration are separate changes in DNA modifications that react to our changing body and other factors. "The novelty of our work originates with the finding that DNA methylation is altered by weight loss," said first author Romain Barrès, of the University of Copenhagen, in Denmark.

Theses changes to DNA make-up occurred on the methylation (chemical markings) of the two genes PGC-1 alpha and PDK4, responsible for controlling fat metabolism and glucose levels.

"We provide evidence that in severely obese people, the levels of specific genes that control how fat is burned and stored in the body are changed to reflect poor metabolic health," said senior author Professor Juleen Zierath, of the Karolinska Institutet, in Stockholm, Sweden. "After surgery, the levels of these genes are restored to a healthy state, which mirrors weight loss and coincides with overall improvement in metabolism."

The entire study was published in the April 11 online edition of Cell Press' journal Cell Reports.