People living in Northern Ireland and Scotland can expect to spend a smaller proportion of their lives in good health than their English and Welsh neighbours, new figures suggest.
The amount of life spent in good general health is increasing in England and Wales but falling in Scotland and Northern Ireland, according to data from the Office of National Statistics (ONS).
And health authorities in Scotland and Northern Ireland should expect increasing demands on services, researchers concluded.
Boys born in England between 2008 and 2010, who are expected to live to the age of 78, are estimated to spend 64 years in good health.
Those born in Scotland, who are expected to live for almost 76 years, have a "health life expectancy" of just under 60 years, data shows.
Similarly, girls born in Wales between 2008 and 2012 can expect to live 63 of their estimated 81.7 years of life in good health. The number of years spent in good health for girls born in Northern Ireland is 61.9.
The authors said: "These findings indicate that Scotland and Northern Ireland may face proportionally greater future demands on health services than England and Wales due to the well established link between self-rated health and subsequent mortality and health service use."
While life expectancy continues to increase across the UK, researchers wanted to assess whether the additional years were spent in good or bad health.
Across the UK as a whole, people can expect to spend more than 80% of their lives in good or very good general health.
For boys born between 2008 and 2010, they could expect to live 63.5 years in good health - 81% of the life expectancy of 78.1.
The average time for girls to live in good health was 65.7 years - 80% of the female life expectancy of 82.1.