Scots parents filling their trolleys with junk food because offers and bargains, new research by Cancer Research UK has found.

Shoppers were asked how much offers on foods high in sugar, salt or fat influenced their shopping choices.

In a survey commissioned by the charity, researchers found 89 per cent of parents believed supermarket promotions impacted what they buy.

Meanwhile almost 57 per cent of parents said promotions lead them to buy more junk food than they really want.

The survey also revealed 71 per cent think too much junk food is on promotion in supermarkets.

Around three quarters of parents would like to see that balance shifted towards healthier items.

Professor Linda Bauld of Cancer Research UK, who is based at the University of Stirling, said: "These offers are persuading parents to ignore their shopping lists and buy cheap unhealthy food in large quantities.

"And if that junk food sits in our kitchen cupboards, we're tempted to keep reaching for it, even if it's been bought as a treat.

"The consequence of this fatty and sugary food can be seen on growing waistlines across Scotland."

Multi-buy offers, the charity says, could affect what type of foods parents are feeding their families.

They have also led to a rise in obesity and are linked to 13 different types of cancer prompting calls for strong action from the Scottish Government when it publishes its obesity strategy later this year.

The Cancer Research UK poll, conducted by Survation, quizzed 1,037 Scottish adults in June 2017 on their attitudes towards purchasing junk food.

It also found 78 per cent of parents had bought either food or drink that was on a multi-buy offer in the last month.

Mother-of-three Susan Shaw, 61, of Edinburgh said: "I think we would all welcome a nudge in the right direction and if the Scottish Government banned the sale of unhealthy food at cheap prices we'd all get on a lot better.

"If the offers were instead focused on fruit and veg, good quality meat, fish, as well as healthy snacks, people would be encouraged to eat better because these items would be available at a good price."

Professor Bauld called on the Scottish Government to urgently restrict supermarket multi-buy offers and promotions on unhealthy food.

She added: "As part of its expected obesity strategy, the Scottish Government has an opportunity to help families make it easier to keep a healthy weight.

"By restricting special offers on unhealthy food and drink, we can make our shopping baskets healthier."

A spokesman for the Scottish Government said: "Tackling obesity is a top priority for this government and we will consult on our new diet and obesity strategy this year.

"We are absolutely committed to reducing the deeply ingrained health inequalities which persist in Scotland and it is important we take the time to get our approach right, taking into account the views of a wide range of stakeholders.

"We continue to engage with the food and drink industry on action to offer healthier choices, including rebalancing promotions and reducing added sugar.

"We recognise the need to shift the emphasis from dealing with the consequences of a poor diet to tackling the underlying causes, which is why we have consistently called on the UK Government to ban junk food advertising before the 9pm watershed, a move we believe would greatly reduce children's exposure to the marketing of unhealthy food and drink."