A charity is warning that obesity is now the leading cause of four cancers.

A charity is calling for urgent action on obesity after research revealed there are almost twice as many dangerously obese people in Scotland than smokers.

Cancer Research UK (CRUK) said there are 1,270,000 obese adults in Scotland - around 29% of the population - compared to around 640,000 non-obese smokers.

Although smoking remains the nation’s biggest preventable cause of cancer, the charity’s analysis found being overweight or obese trumps smoking as the leading cause of four cancers - bowel, kidney, ovarian and liver.

The research is being published as CRUK launches a new UK-wide campaign to increase awareness of the link between obesity and cancer.

The campaign compares smoking and obesity to show how policy change can help people form healthier habits.

In addition, the charity is calling for the Scottish Government to take action as part of its forthcoming obesity strategy.

Gregor McNie, Cancer Research UK’s head of external affairs in Scotland, said: “There isn’t a silver bullet to reduce obesity, but the huge fall in smoking over the years – partly thanks to advertising and environmental bans – shows that government-led change works. It was needed to tackle sky-high smoking rates, and now the same is true for obesity.

“The Scottish Government must do what it can to make it easier for people here to live a healthier life. In its next Programme for Government, a commitment to introduce laws to restrict the junk food multibuy price promotions that tempt us to eat too much would go a long way to helping us to do a healthier shop.”

The campaign will see posters inspired by old fashioned cigarette packs go on display at prominent sites across Scotland.

CRUK said the message is not to compare obesity with smoking, but to encourage people to make informed choices to lead healthier lives.