The number of obese children and adults in England is still on the increase, despite the government's drive to get people to eat healthily and exercise more, it emerged today.

Nearly a quarter of men and women were obese last year, according to the Health and Social Care Information Centre.

The rate of obesity in men almost doubled in 11 years - from 13.2% in 1993 to 23.6% in 2004. In women the increase was slightly lower - from 16.4% in 1993 to 23.8% in 2004.

The study showed that young people's body mass index (BMI) - a measure of weight in relation to height - was also rising.

The report showed that since 1995, the average BMI for boys increased from 17.6 to 18.1 in those aged two to 15. Over the same period, girls' average BMI increased from 18 to 18.4.

The report said: "This rise, although small, is nevertheless an indicator that children in England are on average getting bigger."

The increase in obesity came despite people eating more fruit and vegetables and doing more exercise.

The proportion of adults eating a minimum of five portions of fruit and vegetables a day rose from 22% to 24% for men and 25% to 27% for women between 2001 and 2004.

The proportion of men taking a minimum of 30 minutes of at least moderate exercise at least five times a week increased from 32% to 35% between 1997 and 2004, while in women the rate increased from 21% to 24%.

The study, involving around 8,000 adults and 2,000 young people aged two to 15, also found a drop in the number of smokers, and rising rates of alcohol consumption among young men and women.

· The decision by some NHS trusts to deny hip and knee replacement surgery to obese patients was condemned as underhand "rationing" by a senior doctor today.

Nicholas Finer, a consultant in obesity medicine at Addenbrooke's hospital in Cambridge, said there was no evidence to support the ban on obese people undergoing such surgery as imposed by the NHS in East Suffolk.

In a letter to the British Medical Journal, he wrote: "No evidence supports withholding joint replacement from obese people, even on utilitarian grounds."