Leading medical experts are recognising obesity as a disease and urgently calling on the government to do the same.

Talking exclusively to Sky News, the Royal College of Physicians (RCP) said until obesity is recognised as a disease, rather than a lifestyle choice, its prevalence is unlikely to be reduced.

President of the RCP, Andrew Goddard, said: "We've come to realise obesity isn't a lifestyle choice - it's something people have a genetic predisposition to and it depends on the environment we live in."

He added: "Recognising it as a disease allows people to see they have a disease and reduces the stigma of having obesity."

According to the World Health Organisation, 30% of adults in the UK are obese and that number has tripled since 1980, making the UK the most obese country in western Europe.

Statistics from NHS Digital show the health service spends around £6bn a year treating obesity, a condition responsible for more than 30,000 deaths each year.

Sarah Le Brocq, 36, is obese and supports the reclassification of obesity as a disease, insisting her weight is not down to a lack of willpower or a lifestyle choice.

Image caption: Sarah Le Brocq has struggled with her weight for as long as she can remember

Five years ago Sarah took part in a tough training programme and starred in Sky Living's Fat: The Fight Of My Life, losing eight stone. She said she was happier for a while but it didn't last.

"I have had phases where I have lost significant amounts of weight and I thought that was the answer, that this is it, I wasn't obese anymore. But it wasn't," she said.

Sarah believes that by recognising obesity as a disease, it will challenge the misconceptions and make people realise the cause is not as simple as overeating.

She said: "Too many people look at other people who are overweight or obese and think it's their fault, that they made that choice. But I can tell you, I haven't chosen to be like this, obesity is something that has happened to me."

Professor Rachel Batterham specialises in obesity research for University College London and agrees that obesity is a chronic, progressive disease. She believes classing it as such is the only way to treat the cause rather than the consequences of the obesity crisis in the UK.

She said: "We know the biology now and there are over 100 DNA that have been identified showing how some people will develop obesity and others will be protected.

"We also know that once a person has developed obesity it's almost impossible to lose that weight and keep it off. The body will do all it can to go back to the highest weight you've ever reached."

The decision to recognise obesity as a disease would require a radical overhaul of the NHS. It would need a national strategy, more funding and the use of long term medication to treat patients.

Some experts, including David Buck from the health think tank, The Kings Fund, said the classification isn't necessary and risks over-medicalising what is a lifestyle choice for many.

He said: "I do think this could have dangerous consequences.

"Obesity isn't a disease, it's a condition, an outcome. I am slightly overweight, according to government statistics, but I don't see myself as suffering with a disease. It's because of the environment I live in, the choices I make. It's a condition not a disease, I don't buy that at all."

Dr Fiona Gillison, from the University of Bath said: "The idea of obesity as a disease has got some advantages in terms of treatment and taking the issue more seriously but it can be problematic for those who aren't heavily obese as it can medicalise what is actually a normal experience for most of us and being physically active is something we all would want to do as part of daily life.

"It can also be off-putting, particularly to parents when we are saying children have a disease if they are overweight or obese."

The Department of Health and Social Care said: "We are committed to reducing obesity and the harm that it causes.

"That's why NHS England's Diabetes Prevention Programme will double as part of the upcoming long-term plan for the NHS - over 200,000 people every year across England will have access to targeted weight loss support and advice.

"We're also helping people to live healthier day-to-day lives - as part of our obesity plan we've encouraged manufacturers to cut sugar from half the drinks available in shops and are consulting on plans to introduce calorie labels in restaurants.