Supermarket bosses are being urged to do more to combat child obesity in Scotland.

The SNP's health spokesman, Shona Robison, has called on retailers to support a "traffic light" system which warns parents against unhealthy food.

The MSP has introduced a piece of legislation entitled the Nutritional Composition and Value of Food and Drink (Scotland) Bill.

Tesco has already agreed to pilot the system and Robison has written to other retailers calling for their support.

"Every parent in Scotland wants to ensure that their child has the best start in life, and healthy eating is one of the main ways that they can do that," she said.

"The traffic light system is aimed at making life easier for busy parents because they can see at a glance what is good for their children and what is not."

"Often, parents are subjected to pester power from their children, and do not have time to calculate exactly what is contained in every product they buy, this is where the traffic light system will help."

Robison has also issued a call to arms to her fellow MSPs as they prepare to return from summer recess.

"Childhood obesity in Scotland is increasing and both supermarket chains and the Scottish Parliament must set a good example to stop the problem becoming any worse," she said on Wednesday.

"We must promote healthy eating among the young so that we can try and crack down on health problems that can affect people in later life."