Reducing food waste could save households almost £40 a month, according to a new campaign.

We throw away around one fifth of the food we buy every year - creating around 630,000 tonnes of waste which gives off harmful greenhouse gases.

Zero Waste Scotland said that as well as helping the environment, reducing what we toss in the bin could result in savings of £470 a year.

A new campaign aims to get Scots to "shop smarter" and recycle foods that cannot be eaten like banana skins, bones and tea bags.

Iain Gulland, director of Zero Waste Scotland, said: "Food waste that cannot be used or avoided is easily recycled or composted.

"Over half of households across the country now have access to food recycling services and councils are continuing to roll these out in towns and cities nationwide. Recycling food waste can also generate renewable energy and be turned into a fertiliser to benefit Scottish farmers."

The Scottish Government has pledged to cut greenhouse gas emissions by 42% by 2020 and 80% by 2050. This includes a ban on food waste from landfill sites by the end of 2020.

Environment Secretary Richard Lochhead said: "If we used up all the food and drink we currently waste, it would cut carbon emissions equal to taking one in four cars off Scotland's roads.

"The best thing we can all do is to prevent food waste, but sometimes it can't be avoided. As well as helping people to reduce food waste, this year's campaign is encouraging Scots to recycle the food they can't use, by using food waste collection services which have now been rolled out in more than 50% of the country, or by composting at home where these services aren't available.

"By reducing the amount of food that ends up in landfill, we'll be cutting harmful greenhouse gases."

The campaign comes a month after new waste regulation rules made it compulsory for all Scottish businesses to recycle key materials including food waste.

The website greenerscotland.org offers tips on wasting less food, advice on composting and the availability of local food waste collections.