Increases in life expectancy in the UK have stalled and the slowdown is one of the biggest among 20 of the world’s leading economies, ONS data shows.
Rises in life expectancy in the UK dropped from 17.3 weeks per year from 2006 to 2011 to 4.2 weeks per year from 2011 to 2016, its report found.
This rate of improvement was the lowest of the 20, apart from that in the US.
The ONS said the UK drop was partly due to a relatively large increase in male life expectancy from 2001 to 2011.
There was also a slowdown in other countries across Europe, North America and Australia, although Japan saw its life expectancy increases go up.
By BBC News health editor Hugh Pym
Life expectancy has been rising in recent decades – but from 2011 the rate of increase started to slow in many countries.
Now we know that slowdown has been more pronounced in the UK compared with several other leading economies – so the question arises are there factors peculiar to the UK at work?
Some academics argue that government austerity policies must have played a part, for example cuts in social care budgets in England.
They are calling for a parliamentary inquiry with experts giving evidence.
Ministers say no such causation can be proved.
Some will point out the US has seen a similar slowdown with a very different set of economic policies.
This ONS report is the first such international analysis for a while and raises big questions about health outcomes and government policy in the UK.