People must do more to look after their health and stop preventable conditions draining NHS resources, the Welsh chief medical officer has said.

Launching his annual report, Dr Tony Jewell said the NHS must become more efficient and cut out waste to cope with increasing financial pressure.

But he made clear that individuals also had a responsibility to look after themselves as the NHS was forced to pick up the cost of drinking, smoking and obesity.

Dr Jewell called for smoking to be banned in cars carrying children to protect them from second-hand smoke; he highlighted an estimated 2,500 excess winter deaths in 2008/09, up 74% on the previous year, and he backed calls for the Welsh Assembly to have the power to introduce minimum prices for alcohol to tackle a binge-drinking culture.

Dr Jewell said: “Individuals must also do more for themselves.

“We can only tell people so much of the harms of smoking and drinking and the importance of eating a healthy diet and doing regular exercise.

“But more and more people require treatment for conditions related to obesity, smoking and alcohol abuse - preventable conditions that are draining the resources of the NHS.”

His plea for a more efficient service follows comments this week from First Minister Carwyn Jones that a guarantee to ring-fence all health spending would be “irresponsible”.

Although the administration will protect hospitals from cutbacks emanating from Westminster, Mr Jones said the same promise could not be extended to the rest of the NHS.

Ministers have predicted that spending cuts could force the NHS to find savings of almost £2 billion over the next five years.

Opposition AMs have made repeated attacks on spending since NHS finance directors last year told a cross-party committee that around a fifth of the health budget - some £1 billion - was not spent properly.

Dr Jewell said: “The NHS has, and always will be, a priority for the Assembly government - demonstrated by 40% of our budget being invested in health and social services.

“However, we must continue to work to become more efficient and effective in the way we deliver services in order to improve patient safety, sustainability and clinical quality.”

Unnecessary procedures and hospital infections must end, he said.

“Treatments need to be evidence-based, rather than undertaken simply because they have become accepted practice over time,” he added.

“Waste must be cut out. It is estimated that up to 50% of prescribed medicines are not taken as intended or at all by patients, and in September we launched a campaign to encourage people to reduce the amount of medicines they do not use or throw out.”

Clinicians must do their best to adopt best practice or justify why they have not, and patients need help to understand the reasons behind their treatment, he said.