One in 10 NHS trusts restricts operations for obese people or smokers, according to a TV investigation.
Sixteen of the 152 primary care trusts (PCTs) in England have policies restricting non-emergency surgery such as hip replacements, according to a report on ITV1's Tonight With Trevor McDonald programme.
Out those, eight PCTs had restrictions based on a patient's weight; one restricted surgery to smokers; and a further seven NHS trusts restricted operations to smokers and to obese patients.
Guidelines published by the government's drug rationing body, the National Institute for Health and Clinical Excellence, allow trusts to take patients' lifestyles into account in deciding if a treatment would be effective.
But critics interviewed for the programme, Too Fat For Treatment, said care was being restricted on the basis of poor evidence or on financial grounds.
Dr David Haslam, who devised the guidelines for obesity management in primary care in the UK, told the programme: "Technically speaking, a BMI of 30 plus means that you're obese. But that figure in itself tells us very, very little about fitness and your medical risk.
"You can have a BMI of 35 and be absolutely the fittest person on the planet because you're fit, you're muscular, you've got wide shoulders; you've got a narrow waist. Whereas a bloke for instance with stick arms and stick legs but a big belly, may not be obese in terms of BMI but there are too many high risks in terms of medical risk because of their abdominal circumference."
Michael Summers, the chairman of the Patients Association, said it was clear that patients were being deprived of treatment on financial rather than clinical grounds.
"That is never acceptable in our view," he said. "Merely to send patients away because they are smokers is morally wrong and contrary to the rules."
However, the Department of Health denied that smokers or obese people were denied operations to save money.
It told the programme: "If a clinician believes that a patient will have better outcomes from surgery if they change their lifestyle then they are right to make that decision on clinical grounds."
The PCTs with restrictions on non-emergency operations due to a patient's obesity are: County Durham; Herefordshire; Halton and St Helens; Stoke; west Hertfordshire; east and north Hertfordshire; Suffolk; and Norfolk.
Stockport PCT restricts non-emergency surgery on the basis of a patient's smoking habit.
And the PCTs which restrict non-emergency operations due to obesity and smoking habits are: Bedfordshire; Kensington and Chelsea; west Essex; Lincolnshire; north Lincolnshire; Milton Keynes; and north Staffordshire.
· Too Fat For Treatment is on tonight at 8pm on ITV1