Nearly 80 per cent of all cardiovascular diseases could be prevented if people improved their diet and lifestyle, Watchara Panchet, an assistant to the health minister, told a meeting of 300 medical professionals at Bangkok's Richmond Hotel.

Watchara said the main causes of such diseases were obesity, diabetes, high blood pressure, high cholesterol, lack of exercise, not enough fruit and vegetables and smoking.

He said a 2004 survey of people over the age of 15 found that over 39 million Thais ate less than the internationally recommended amount of fruit and vegetables each day.

Eleven million said they smoked every day, and 10 million said they did not exercise. And 70 per cent of those questioned did not know they already had high blood pressure, he said.

There were now 125,000 patients for every heart doctor, Watchara said, so preventive measures would be more effective than treating problems after they arise.

The Public Health Ministry will launch a campaign called "rak hua jai tawai Nailuang" (love your heart out of respect for His Majesty the King) to mark this year's World Heart Day on September 24, Watchara said.

The campaign will include walking marathons at Suan Luang Rama IX Park and at the Public Health Ministry's office in Nonthaburi, along with activities like check-ups, exhibitions and shows. The event will run from 5.30am to 2pm.

Privy Councillor Kasem Wattanachai said the number of cardiovascular deaths were second only to cancer among Thais.