Not fit? Blame it on genes

In what could cheer the couch potatoes a bit, researchers have now found that genetic cells in our bodies keep changing and they could influence our health in numerous ways.

Genomes are changing, not just from generation to generation, but even and in fact within our individual cells.

The researchers found an association between the level of modification of RNA and our basal metabolic rate - the rate at which we are able to convert food into energy to power our bodies.

If DNA is the printing press that determines the functions of a living organism, RNA is the print that it leaves behind.

Modifications to the RNA of the mitochondria might be influencing your fitness, discovered the researchers.

"Mitochondria are the power stations of our cells, and the more power a cell needs, such as a muscle cell, the more mitochondria it has," said Alan Hodgkinson from the University of Montreal, Canada.

"The many mitochondria in the same cell can have different genetic mutations. Our research helps us to understand how variable mitochondrial RNA processing can be and what the possible consequences of that might be on health," Hodgkinson said.

The findings add extra layers of complexity to our understanding of how genetics influence our health.

"We have determined that our genome's ability to modify itself is partly hard-wired," said Philip Awadalla, director of the Canada-based CARTaGENE initiative, one of the world's most comprehensive banks of genetic information.

The study involved data of 1,000 participants from Canada, making this the largest RNA sequencing in the world to date.

The study appeared in the journal Science.