Hywel Griffith BBC Wales health correspondent

Chronic disease rates are high among obese adults

These include arthritis, asthma, diabetes and heart disease. However, they cannot be cured, but only managed by doctors.

That means they take up a huge amount of NHS time and money, and with the problem worsening, what can be done?

The answer chosen by the Welsh Assembly Government is encouraging healthy lifestyles with a balanced diet. But will it be enough?

We are very good at treating heart disease but we've got a massive amount of work to do in terms of prevention, especially with children June Davison, British Heart Foundation

Wales does not stand alone in facing the problem. A World Health Organisation report stating that "the lives of far too many people in the world are being blighted and cut short by chronic diseases," with "the cost of inaction is clear and unacceptable".

But with a devolved responsibility for health, it is up to the NHS here to take action.

In January 2005, Health Challenge Wales was launched, promoting regular exercise, a balanced diet and quitting smoking. The idea is to help people to help themselves.

In April 2007, a ban on smoking in public places will follow. It is a more heavy-handed approach, in trying to force people to make decisions about their own health.

Increased risk

Heart disease is one of the biggest concerns, with chronic conditions leading to fatal problems later in life.

CHRONIC DISEASES 23.3% of the Welsh population have long-term limiting illness 80% of GP consultations relate to chronic illness 17.5m people in UK have a chronic disease

"If someone has coronary heart disease, it puts them at increased risk of heart attack in the future," said cardiac nurse June Davison of the British Heart Foundation.

She believed that waiting until someone had a problem was too late, with a cultural shift needed.

"We are very good at treating heart disease," said Ms Davison, "but we've got a massive amount of work to do in terms of prevention, especially with children".

The recent focus on school food shows the public and politicians are beginning to realise the scale of the challenge. Changes made now will decide chronic disease rates in 40 years.

Next generation

But Welsh children do not compare well with others when it comes to chronic diseases.

About 55,000 children in Wales have asthma, with more under-14s being hospitalised by the condition than anywhere else in the UK.

"In recent years the prevalence in Wales has increased as elsewhere due to a greater awareness of the condition," warned Dr Grant Benfield from Ysbyty Gwynedd, Bangor, "but also because there appears to be a true increase in the incidence of new asthmatics".

He said the NHS had to ensure it had the resources to support patients, and prevent further problems.

"Asthma sufferers are best served through easy access to expertise, usually specialist nurses, in primary care to ensure good understanding by the patient and adequate preventative treatment."

With no cure for chronic diseases, the onus must be on prevention.

Persuading the public - young and old - to take control of their own health is the key, but may take generations to achieve.