As more adults in the UK become obese, in fact one third of the adult population within four years so to will the numbers of people who will suffer from potentially deadly diseases, including diabetes, heart disease and some forms of cancer, experts warn. Nearly one in four adults within the UK are classed as obese, but this will rise further to 13 million adults in England - one in three - being classed as obese by 2012, scientists led by a team from University College London (UCL) estimate, based on current trends. Almost half of them will come from low income or disadvantaged communities, the researchers warn. Dr Paola Zaninotto, from the department of Epidemiology and Public Health at UCL, who led the study, warned that obesity is a "major public health problem which can lead to premature death because of its associations with serious chronic conditions such as Type 2 diabetes, high blood pressure and cancer". She added: "There is an urgent need now to reverse this trend towards obesity and there are no signs, as yet, that it is reversing." The researchers estimate that obesity costs the British economy between £6.6 billion and £7.4 billion every year. In 1993 just 14 per cent of men and 17 per cent of women were obese, the study, published in the Journal of Epidemiology and Community Health, shows. By 2000, that figure had crept up to almost 20 per cent for both sexes. The researchers made their estimations based on annual data collected between 1993 and 2004 for the Health Survey for England, which looks at almost 128,000 adults across the country. Here are the top twenty 'fattest' places in the UK: 1. Shetland 2. Torfaen 3. Blaenau Gwent 4. Neath 5. Caerphilly 6. Rhondda 7. Barnsley 8. Wrexham 9. North Lincolnshire 10. Merthyr Tydfil 11. Denbighshire 12. Doncaster 13. Carmarthenshire 14. Stoke-On-Trent 15. Wolverhampton City 16. Anglesey 17. Blackpool 18. Knowsley 19. Newport 20. Northumberland Care Trust And here are the top twenty 'slimmest' places: 1. Camden 2. Richmond & Twickenham 3. Wandsworth 4. Kensington & Chelsea 5. Westminster 6. Hammersmith & Fulham 7. Brighton & Hove 8. Surrey 9. Kingston 10. Tower Hamlets 11.Lambeth 12. Bristol 13. Bath & North East Somerset 14. Lothian 15. Buckinghamshire 16. Barnet 17. Islington 18. West Hertfordshire 19. Bromley 20. West Sussex