A new survey today reveals that 97 per cent of people in Britain are unaware that their beer bellies and muffin tops are generating higher levels of oestrogen and excess chemicals in their stomachs, putting them at risk of cancer, Type 2 diabetes and heart disease.

Worryingly, nearly three quarters (71 per cent) of people admit to carrying excess weight around their middle, and more than half (57 per cent of women and 55 per cent of men) overestimate the waist measurement at which they become at risk.

The results of the survey, which questioned 2,085 adults in Great Britain, were released as Diabetes UK, Cancer Research UK and the British Heart Foundation (BHF) launched their new ‘Active Fat’ campaign to raise awareness of the dangers of carrying extra weight around your middle.

The charities are urging people to measure their waistlines and make positive changes to their lifestyles if they are at risk.

They have also produced a new web animation featuring a sinister fat cell, which helps to show people that instead of lying around harmlessly, our fat cells are actually very active and working around the clock to stimulate disease.

Dr Mike Knapton, Associate Medical Director for the British Heart Foundation, said: “That ‘harmless’ spare tyre around your waist is actually a major health hazard. While you might be relaxing at home, your fat cells are working overtime to pump out excess hormones and other chemicals that can cause disease.

“Wrapping a tape measure around your middle takes just a few seconds, but it could be your vital first step towards a healthier a future.”

The campaign is being supported by former ‘Apprentice’ television contestant and business woman Claire Young.

Ms Young said: “As someone whose family has been affected by heart disease and Type 2 diabetes, I know just how important it is to look after your health. My mum and I recently reduced our waistlines by making small, everyday changes to our lifestyles, and I’m encouraging others out there to measure their own waistlines and make changes if their health is at risk.”

The charities are also calling for the European Parliament to support people to make healthier food choices by bringing in a single front-of-pack food labelling system across the EU, which includes traffic light colours.

Diabetes UK Care Advisor Libby Dowling said: “If you’re used to pounds and ounces, it’s extremely confusing to go into a shop that only deals in grams and kilograms. It’s the same with food labelling systems - we need one system that includes traffic light colours to help busy supermarket shoppers make informed food choices.”

Professor Jane Wardle, director of Cancer Research UK’s Health Behaviour Research Centre at University College London, said: “Little changes that can become daily habits are the best, as they usually require less effort and can act as the building blocks of a much bigger lifestyle picture. Waist size is likely to increase throughout life, so whatever your age, today is a good day to start improving your health.”

The survey also found that women were less likely than men to worry about their health as a result of carrying excess weight around their middle (41 per cent of women compared to 50 per cent of men), and more likely to worry about how they look (28 per cent of women to 18 per cent of men) and fitting into their clothes (18 per cent of women to 9 per cent of men).

Less than half of men and women (44 per cent) have tried doing more physical activity in response to carrying excess weight around their middle.

More than a quarter of people (27 per cent) have bought bigger sized clothes, approximately one in seven (15 per cent) have covered up on the beach, and approximately one in eight (12 per cent) have avoided weighing themselves altogether.

To help people to trim their tummies, Cancer Research UK, Diabetes UK and the British Heart Foundation are sharing their top tips on losing weight through their joint campaign website.

People can learn more about active fat and take a lifestyle check at www.activefat.org.uk