Researchers from the University of Glasgow have been studying thousands of Scottish schoolchildren to determine whether genetic factors cause inactivity and obesity.

The research builds on an earlier Glasgow University study which revealed a single gene can determine whether a fruit fly is an energetic "rover or an inactive sitter".

People could be helped to be more energetic

Scientists have initially been focusing on seven genes that they believe could be important.

It is hoped that in future people who have the so-called lazy genes could be given special diets and exercise programmes to help them remain healthy.

Dr Yanis Pitsiladis, who is leading the study, said people now eat fewer calories than they did 30 years ago.

He said that means increasingly sedentary lifestyles are the most likely cause of people becoming overweight.

Mary Allison, Scotland's newly appointed fitness tzar, said: "We are a long way from finding any kind of genetic solution to inactivity, if indeed it would ever exist.

"The simple message is there is something you can do today and that is take more simple physical activity, walk more, take the stairs instead of lifts and any other opportunity that comes your way to be more active."