The average British adult spends more than 20 hours a day sitting or lying down, a survey from Weight Watchers has found.
Its results show that 67 per cent of people spend the majority of the day sitting or lying down whether awake or asleep.
However the data also showed that 54 per cent of adults thought they lead a busy and active life.
The findings come a week after a report by walking charity Ramblers suggested a quarter of Britons only walked one hour a week and supports the belief that the UK is becoming more sedentary.
Technology causes ‘mental tiredness’
Zoe Hellman, head of public health at Weight Watchers UK, believes the rise in the use of modern technology such as smartphones, where adults are constantly "switched on", was leading to mental tiredness.
Hellman said: "We’re constantly texting and emailing as well as browsing online, it’s mentally exhausting and people don’t know the difference between mental tiredness and physical exertion."
The poll of 1,000 UK adults found that 83 per cent or 18 to 24-year-olds would check their mobile phones at night after they have gone to bed and 71 per cent do it again when they wake up in the morning.
In 2012 Ofcom found that texting had overtaken actual phone calls for the first time.
And Weight Watchers found that 45 per cent of adults feel obliged to respond to work emails outside of work time, increasing the feeling of being constantly busy and tired.
Due to mental exhaustion, this technology-led lifestyle leads many people to reach for sugary drinks, coffee and chocolate bars to refuel.
Television viewing times rise
Weight Watcher's figures showed that people were watching more television each day than seven years ago.
In 2006, the average viewing times per day were 3 hours and 35 minutes for adults – compared with 4 hours and 2 minutes today.
"We’re doing little or no activity to burn off this excess energy consumption.
"And as sedentary lifestyles seem to be on the rise, the UK’s obesity rates continue to escalate," Hellman said.
Sitting increases death risk
In 2012, scientists from Leicester and Loughborough universities found that prolonged periods of sitting down increased the risk of diabetes, heart disease and death.
Prof Stuart Biddle of Loughborough University said: "There are many ways we can reduce our sitting time, such as breaking up long periods at the computer at work by placing our laptop on a filing cabinet."
In January 2013, expert exercise scientists said standing an extra three hours a day would burn off as much as 8lb of fat a year.
Humans designed to keep moving
John Buckley from the University of Chester found that standing up for three hours burns off 144 calories and believed sitting down for such long periods isn’t natural.
Buckley said: "People are sitting down at work, then sitting in the car and then sitting down in front of the television.
"Your metabolic rate crashes to an absolute minimum. It isn't natural. Humans are designed to stand up and keep moving."
By maintaining a healthy weight and keeping a balanced lifestyle you can keep your health insurance premiums low.
Some policies even incentivise their customers to stay fit with discounted gym memberships and stop smoking sessions.