Life expectancy at birth has stalled for the first time since modern records began, according to the Office for National Statistics (ONS).
Figures released today (25 September) showed life expectancy at birth stood at 79.2 for a man and 82.9 for a woman in 2017.
This marked a decline of 0.1 years between 2015 and 2017 for males and females in Scotland and Wales, and for males in Northern Ireland when compared with figures from 2014 to 2016.
It remained unchanged for females in Northern Ireland and males and females in England.
Life expectancy from age 65 has also not improved - a typical man of this age can expect to live for another 18.5 years, and a woman for 20.9 years.
According to Sophie Sanders, statistician at the ONS Centre for Ageing and Demography, 2015 to 2017 saw the lowest improvements in life expectancy since the start of the series in 1980 to 1982.
She said: "This slowing in improvements is reflected in the chances of surviving to age 90 years from birth, which has also seen virtually no improvement since 2012 to 2014."
Alistair McQueen, head of savings & retirement at Aviva, said despite today’s stall, individuals were still set to live longer than ever before.
He said: "We must prepare for this future, by saving more and readying ourselves for a longer working life."
Aviva's research from 2015 found individuals were poor at estimating life expectancy with women underestimating their life expectancy by up to 8 years, and men by up to 5 years.
Underestimating life expectancy can result in people running out of private savings in later life, with their only fall-back being the state pension, the provider warned.
Jon Greer, head of retirement policy at Quilter, stressed "a plateau should not be mistaken for a decline".
He said the ageing population was putting additional pressure on public finances and those looking after their ageing family members.
He said: "With the social care system inadequately equipped for an increasingly ageing population, and insufficient pension provision beginning to crystallise, policymakers and businesses will be monitoring life expectancy trends closely.
"It’s critical people are realistic about the possibility of surviving into their 90s."
Separate data from the ONS, also released today, showed there were 579,776 people aged 90 years and older living in the UK in 2017, representing an increase of 8,531 from the year before.
On the other hand, the number of people aged 100+ fell. In 2017 there were 14,430 people aged 100 or older, compared with 14,910 in 2016 - a drop of 3 per cent.
This was the first time the number of people in this age group fell since the data began in 2002.
According to Nathan Long, senior analyst at Hargreaves Lansdown, improvements in healthcare were behind the rising number of people in their 90s.
He said: "While the number of people aged over 100 has fallen, this is seen as a blip in a longer upward trend, caused by the low number of people being born during World War I.