'Tis the season to eat, drink and be jolly, but health experts warn that each day of over-indulgence can cut a several hours off your lifespan.

A new statistical report, published in the British Medical Journal, finds that activities like smoking, having a couple of drinks, eating red meat and sitting in front of the television can take at least 30 minutes off a person's life expectancy for every day they indulge.

However, researchers note that each day of sticking to just one alcoholic beverage, eating plenty of fruit and vegetables and exercising can add up to two hours to a person's life.

Professor David Spiegelhalter, a statistician at the University of Cambridge, quantified the impact of different behaviors on a person's lifespan using a concept of accelerated or decelerated aging.

Spiegelhalter expressed the daily effects of lifestyle habits as "microlives" or half hours of life expectancy, explaining that 30-minutes of adult life expectancy roughly translates to one millionth of life after age 35.

Using data pooled from previous population studies, he calculated that a person can lose 30 minutes of their life just by smoking two cigarettes, being 5 kg (11 lbs) overweight, having more than two alcoholic drinks a day, watching two hours of television, or eating a burger.

However, it's not all bad news as microlives can be gained by sticking to just one alcoholic drink a day, eating fresh fruit and vegetables, exercising, and taking statins.

Spiegelhalter found that demographic factors can also be expressed in microlives. For instance, being a woman can add up to 4 microlives a day, being a Swedish man rather than Russian man can add 21 microlives a day and living in the 2010 rather than 1910 translates to a gain of 15 microlives a day.

Spiegelhalter hopes that expressing behaviors in "lost" and "gained" microlives will help the general public to make rough but fair comparisons between the sizes of chronic risks and encourage healthy lifestyle behaviors like quitting smoking.

"So each day of smoking 20 cigarettes (10 microlives) is as if you are rushing towards your death at 29 hours rather than 24," said Spiegelhalter.

He notes that while his latest assessments of different behaviors on a person's lifespan is based on rough approximations, they "bring long term effects into the present and help counter temporal discounting, in which future events are considered of diminishing importance."

Despite the study's limitations, "a reasonable idea of the comparative absolute risks associated with chronic exposures can be vividly communicated in terms of the speed at which one is living one's life," Spiegelhalter concluded.

"Of course, evaluation studies would be needed to quantify any effect on behavior, but one does not need a study to conclude that people do not generally like the idea of getting older faster," he added.

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