"Alarming" rates of smoking, alcohol consumption and obesity in Europe could mean the next generation live shorter lives, the World Health Organization warned on Wednesday.

While Europeans are living longer than ever before, increases in life expectancy and declines in premature mortality may "flatten off" if the three big lifestyle risk factors are not dealt with, a senior WHO director said.

In a report on the region's health, the WHO said there remain "unacceptably high" differences in life expectancy between countries, with an 11-year gap between the highest and lowest.