The body is that of a woman who weighed 17 stone despite being 5ft5 tall

Doctors said even cutting through the skin was difficult due layers of fat

The post mortem is the first in the UK to

BBC documentary will show the full effects of obesity on the human body

A chilling BBC documentary showing the post mortem of a 17 stone woman has revealed the full effects of obesity on the human body.

Obesity - The Post Mortem, set to air on BBC Three on September 13, depicts the stomach churning scenes of pathologists slicing open the women and examining her skin, heart, liver, lungs and kidneys.

The body used in the documentary is that of a woman from Long Beach, California in her early 60s who died of heart failure and donated her body to medical science.

The American woman weighed 17 stone despite being just 5ft 5 inches tall. She died of heart failure when she was in her early 60s

'I needed a lot more strength to cut through the tissue which kind of bloomed out in neon yellow,' said a pathologist who cut open the woman's skin

Standing at five-foot and five inches tall she was 17 stone and was morbidly obese.

After having her left arm removed for cremation and ashes returned to her family the woman's remains were sent to medical staff for analysis.

As the team began the post mortem they noted a thick layer of greasy fat that 'felt like butter with a mesh going through it' that was mainly distributed around the belly.

'I needed a lot more strength to cut through the tissue which kind of bloomed out in neon yellow,' said Carla Valentine, technical curator of the museum of pathology at Queen Mary University.

'It made me aware of the fat on my own body and the effect it has.'

The heart bared all the hallmarks of an obese person. Doctors said the heart felt baggy and was a lot heavier than it should have been

Pathologist, Giles Yeo, noted that although some fat is healthy for the body when the 'extra fat looks for somewhere else to go and that is where the damage is caused.'

'The amount of fat you can see tells you how likely the fat is to be doing damage elsewhere.'

After cutting the deceased woman open they then went onto extract the heart which had a number of striking problems.

Pathologist Dr Mike Osborn says: 'The heart feels baggy, when you pick up the heart of someone fit it would be tight and hard like picking up a piece of steak, this is like more like a bag.'

'At 449 grams, it's a heavy heart, despite her weight this woman is quite a petite person and should have a heart of 225 grams so this is much heavier.'

'This is sort of heart you would expect in someone who has heart failure due to high blood pressure'

'This heart has gone from a thick muscle to a paper bag that is not able to pump blood around the body,' he added.

The heavy heart is weighed. The woman died from heart failure which was undoubtedly linked to her weight

The woman's liver also showed the signs of obesity being not as soft as it would be in a healthy person.

'The first thing I saw in the liver marked 'fatty change,' Osborn said.

'It was pinky, soft, like pate. A normal liver is quite soft but not as soft and is much more meaty - the pink int his liver is the fat.'

'The most common cause is alcohol related but we known this lady drank virtually nothing so it's almost certainly obesity.'

'Fatty damage can lead to cirrhosis and cancer but even people who do not develop those can have liver failure.'

After inspecting the woman's lungs the BBC pathologists said they were dripping with fluid which is a sign of pulmonary edema caused by heart failure.

'This would have given a sensation of drowning,' Osborn said during the documentary.

Doctors examine the kidneys. 'If you are obese some fat will end up in your kidneys and they will have to work harder' one of the doctors said

Carla Valentine during the haunting autopsy that was the first in the UK post mortem focused specifically on looking at the effects of obesity on the body

'People with this condition tend to need support for example if someone tells you they have sleep sitting up or with eight pillows that is very indicative of heart failure.'

'Heart failure is different to a heart attack, when it fails it doesn't fail straight away, it fails over time so symptoms are gradual.'

'This lady might have been able to walk up 10 flights of stairs three years ago then only five flights and then struggle up one flight of stairs, it was a progressive disease as the heart became worse and worse,' Osborn continued.

Yeo said: 'If you are not getting enough oxygen in you are going struggle to breathe and get out of breath.

A pathologist with the kidneys in their hands. Having fatty kidneys can cause the organ to fail and lead to diabetes

The kidneys also had the scars of obesity.

'You should be able to see the kidneys and they should have a little bit of fat around them like an edamame bean that you pop out but these had very large fat capsules and lots of extra fat,' said Carla.

Yeo said that obesity can lead to diabetes which can cause kidney failure as the organ can become overworked.

'The kidney is another detoxifying organ and it filters your urine,' he said in the BBC documentary.

'If you are obese some fat will end up in your kidneys and they will have to work harder.'

'If you begin to tip into type-2 diabetes then you will get sugar in your urine because you are unable to deal with glucose.'

'The kidney then has to filter all this sugar that your body can't cope with and it will fail.'

A BBC spokeswoman told the Mail Online that the deceased woman 'consented for her body to be donated to medical science.'

'The only information we have about the women is that she was American, in her 60s, and she died of heart disease,' she added.

Another BBC statement said that the woman knew her body may be used 'for research, and educational use, including being filmed anonymously for scientific presentation.'

Obesity in the UK has been on an upward slope with levels trebling over the past three decades.

According to NHS statistics from 2013 the UK has the most over weight people in Europe with 24.9 of adults weighing more than they should. Ireland is in second place with 24.5% of adults over weight or obese.