The use of ambulances to take obese patients to non-emergency appointments has nearly doubled in the last five years, according to figures highlighted by the Scottish Conservatives.

The Scottish Ambulance Service's non-emergency patient transport service (PTS) had to provide bariatric support for 20,177 patients in 2015/16, up from 11,170 in 2011/12.

The figure was down slightly on 2014/15, when the service provided bariatric support for 20,915 patients.

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The Tories said the figures were more proof that obesity was becoming one of Scotland's major public health crises and putting additional strain on the ambulance service.

Obesity levels could reach 40% by 2030, according to the Scottish Health Survey.

Tory health spokesman Donald Cameron said: "This is yet another indication that Scotland is suffering badly from an obesity crisis.

"The issue is proving itself to be the country's next big public health challenge.

"The ambulance service already works under tremendous pressure and these escalating statistics will only make that worse.

"Of course, all patients have to be helped to these appointments and the vehicles which take them must be adequately equipped.

"But this serves as a further warning that action must be taken to improve the lifestyle and diet of people from all backgrounds and of all ages."

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A spokeswoman for the Scottish Ambulance Service said: "Nationally, we currently transfer just under 900,000 patients to and from their healthcare appointments, of whom approximately 2% may require additional specialist support due to obesity.

"While the number of bariatric patient journeys has steadily increased over the last few years, in the course of 2015/16 we have seen a small decrease in the overall number of bariatric patients conveyed by PTS.

"We continue to invest in training and equipment to ensure bariatric patients receive appropriate care and can be moved safely."

Public health minister Aileen Campbell said: "Obesity rates in Scotland are stable and it is encouraging to note that the number of healthy-weight children has been consistently increasing in the last few years.

"We will introduce a new diet and obesity strategy in 2017, building on our wide range of activity to make it easier for people - including children and their families - to be more active, eat less and eat better.

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"As part of this we are looking at what further effective actions we can take within the powers available to us, including the use of multi-buy promotions, as well as examining a range of actions to improve diet, physical activity and education.

"We are engaging with the food and drink industry on action to offer healthier choices, rebalance promotions and reformulate products, with a focus on reducing calories, salt, fats and added sugar."