People in the UK are living in good health for longer, the Office for National Statistics (ONS) reports.
Healthy life expectancy (HLE) increased by more than two years in the period 2008-10 compared with 2005-07.
The proportion of life spent in good health has increased in England and Wales, but fallen in Scotland and Northern Ireland.
The ONS figures also show that more than four-fifths of a lifetime in the UK is spent in good health from birth.
Ed Jessop, Vice President of the Faculty of Public Health said: ""These figures are encouraging. They show that action on public health works. There is particular success for people living in England.
"But the gap between the health "haves" and "have nots" has widened, particularly for men living in Northern Ireland.
"There are many complex reasons for this, because our health is affected by a range of factors - not just what we eat or drink, and how active we are, but also our work, housing and access to all sorts of facilities.
"We need action now to address the root causes of these health inequalities. With all the changes happening in society and in the economy, as well as major changes to the NHS in England, we must use public health expertise to improve and protect our health, as well as to ensure that NHS services provide quality and value for money."
The report suggests that Scotland and Northern Ireland may face proportionally greater future demands on the health service than England and Wales, as they have a higher incidence of poor health in the population.
Ros Altmann, director of over-50s organisation Saga, said: "The latest figures showing that more of us are staying healthy into later life these days are really something to celebrate. Medical advances have brought such success in helping people live longer. That does also mean re-evaluating our lives too.
"Working longer, keeping active - and saving more if you can - are vital ingredients of managing the ageing population. We need to help older people look after themselves where possible and help younger people appreciate the value of elders.
"The other huge challenge of longer lives is helping people prepare for care needs, either for themselves or their loved ones."
The report also showed a difference between the sexes - the ONS figures show men spend a greater proportion of their lives in favourable health compared with women. However, in recent years this gap has narrowed as the health of women has improved more rapidly than for men.
This may be due to higher rates of obesity, alcohol consumption and smoking among men. The research also suggests mutations in mitochondrial DNA may contribute towards ageing in men but not women.
As the data for the report comes from a self-reported survey, which asks how the individual would define their health, the researchers suggest there may also be a difference in the way men and women view their wellbeing.
The ONS also released on Wednesday figures on the number of workless households - which has fallen for the second year in a row.