The scientists found that mice with the molecule were more likely to be energetic and athletic, while mice without it were more likely to be lazy and put on pounds, the BBC reported Wednesday.

The researchers said the genetic switch in the mice is also found in humans and is believed to have the same effect.

Mathias Treier, a scientist with the European Molecular Biology Laboratory in Heidelberg, Germany, and leader of the research team, said those who fidget end up getting valuable exercise without intending to.

"We're spending energy by doing that -- and this is of course one of the key factors in energy balance," he said.

"Clearly people who have the more fidgeting phenotype are more protected against diet-induced obesity, for example, than people who are more calm."

The research follows a recent announcement by British scientists that they discovered a gene directly linked to obesity.