AMBULANCE bosses have been forced to spend an estimated £3.5 million on specialist equipment to treat Scots patients weighing up to 70 stone.

The move follows a 143 per cent increase in the number of severely overweight patients requiring ambulance treatment - up from around 7,000 in 2010 to more than 17,000 last year.

The extra money spent went towards super-wide wheelchairs, zimmer frames for those weighing up to 50 stone, and extra-strength mats used to drag obese patients who cannot be carried.

The figure also included 690 patient lifting cushions - devices which are inflated under individuals weighing up to 70 stone who cannot stand on their own.

The figures were revealed through a Freedom of Information (FOI) request to the Scottish Ambulance Service (SAS).

Tam Fry, spokesman for the National Obesity Forum, said: "Until the NHS rules are rewritten it has to spend this kind of money.

"You have to remember that there are so many people overweight through no fault of their own, through genetic conditions.

"And there are a lot of people not able to take the onslaught of the food and advertising industry.

"Until that is changed then we have to foot the bill."

He added: "Of course the money should be spent preventing obesity, but unfortunately the prognosis for that doesn't look too rosy.

"The number of patient transfers requiring bariatric equipment has more than doubled since 2010, and that is very concerning - but more concerning is that it will be increasing more."

Documents provided revealed that the SAS currently owns 1,048 pieces of specialist "bariatric" equipment designed for response to overweight patients.

Ambulance bosses bought 16 reinforced zimmer frames, at a likely cost of £1,500, 16 extra wide wheelchairs, which could have cost as much as £46,400, and 151 trolley cots capable of carrying obese patients, which would cost online up to £558,700.

But the most cash is likely to have been spent on 690 patient lifting cushions - inflatable devices which slide underneath obese patients before being filled with air, bringing them to their feet.

Medical retailers charge in the region of £3,095 for the devices, meaning that the SAS is likely to have spent around £2,135,550 on the modified gadgets.

The total estimated cost of the equipment comes in at £3,441,451.

Meanwhile, the documents also revealed that the number of incidents where ambulances are called to work on overweight patients has skyrocketed in recent years.

Figures showed that in the past year first response ambulance crews had to respond to 206 incidents involving overweight patients - up from 56 in 2010-11.

Meanwhile patient transport crews had to transport 17,178 patients using specialist equipment in 2014 - up from just 7,101 in 2010.

Scottish Conservative health spokesman Jackson Carlaw said: "There is no doubt Scotland has an obesity problem that is getting worse and costing our NHS millions of pounds to treat.

"The concern is we are heading towards a tipping point where the NHS will struggle to cope with the number of obese cases.

"The Scottish Government now need to work harder to ensure interventions are made at an earlier stage where it's clear someone has a weight issue."

A Scottish Ambulance Service spokesman said: "We currently transfer over one million patients to and from their healthcare appointments of whom approximately two per cent may require additional specialist support due to obesity. This rate is increasing.

"We continue to invest in training and equipment to ensure bariatric patients receive appropriate care and can be moved safely. The majority of our frontline emergency vehicles are bariatric capable, as are nearly all Patient Transport Service vehicles purchased since 2007."