Middle-aged male office workers spend more time sitting down than pensioners, with large parts of the population "dangerously sedentary", according to new research.

The Edinburgh University study found 45 to 54-year-old men spend on average 7.8 hours per weekday sitting down, compared to 7.4 hours for men aged over-75.

Sedentary work is the main reason for the inactivity, with sedentary time (ST) defined as time spent in any waking activity done while sitting or reclined, including working, eating, reading, watching TV or spending time on a computer.

Women in all age groups spend less time sitting then the over-75s, who spend an average 7.4 hours seated each day.

Experts are calling for action to tackle high levels of ST, which has been linked to health risks including cardiovascular disease and type two diabetes.

Among men, only the youngest group surveyed - 16 to 24-year-olds - are significantly less sedentary than the over-75s on weekdays, spending 6.6 hours a day sitting down.

At the weekend, the weekday situation reverses for both men and women.

Those aged 25 to 54 were the least sedentary, sitting for between 5.2 and 5.7 hours a day, while the over 75s were the most sedentary, at 7.3 to 7.4 hours a day.