Scotland's food watchdog is calling for a retail revolution to help shoppers make healthier choices and tackle the looming obesity crisis.

A report commissioned by Food Standards Scotland (FSS) suggests "radical steps" are needed to change the way food is displayed and promoted in stores.

FSS said action is needed to prevent children following the same habits and poor diets that have led to Scotland's current obesity levels of 30%, which are projected to rise to 40% by 2030.

The report, by the University of Stirling, makes several recommendations including extending the sugar tax beyond soft drinks and standardising information provision to increase awareness of health risks and help customers make decisions.

Dr Gillian Purdon, FSS senior dietary adviser, said: "It is clear that a combination of measures will be needed overall to enable healthier eating.

"Regulation of promotions of high fat, salt and/or sugar food and drink within retail stores and out of home premises should be taken forward as a priority."

Previous FSS findings showed that in Scotland, around 50% of less healthy food categories are purchased on promotion compared with healthier foods, which are around 30%.

The University of Stirling report found that in shops, consumers are "overtly and subliminally bombarded with subtle and not so subtle cues, promotional activities, information and other stimuli".

It added: "Most of this reinforces purchasing behaviour focused on unhealthy products, and thus unhealthy diet, placing the onus to combat this on to the individual."

The study calls for a "more level playing field between healthy and unhealthy products" though warned this will undoubtedly face opposition from retailers and manufacturers, as well as some consumer advocacy groups.

The researchers said: "We conclude that the current context for consumer choice in-store is affecting the health and diet of consumers in Scotland.

"Voluntary and self-regulatory approaches or relying on consumers to make "good" decisions are not having sufficient impact.

"It will thus be necessary to regulate to make the changes have real impact."

Cancer Research UK is also calling for action.

The charity's Gregor McNie said: "Scotland has the chance to lead the way with brave new measures that would result in a healthier nation.

"Proposals for a new obesity strategy are anticipated soon and we urge the Scottish Government to be bold."

Aileen Campbell, minister for public health, said: "We are committed to tackling Scotland's obesity problems and will consult on our new diet and obesity strategy this year.

"I have already been clear that there is no quick fix for this problem, and it's important we take the time to get our approach right."