Vast numbers of people are suffering from 'social jet lag', Twitter study suggests

Lack of sleep can lead to various health problems, including obesity, diabetes and cardiovascular disease

(Getty Images)

Huge numbers of people are suffering from "social jet lag" and might be accidentally disrupting their body clocks, according to new research.

The problem could stop people getting enough sleep and disrupting their schedules, in turn leading to problems like obesity, diabetes and cardiovascular disease, according to researchers.

The new study found that people across the US – and probably elsewhere – are suffering from the problem that afflicts their biological clock.

Social jet lag is a new phenomenon where people shift their sleeping patterns backwards and forwards during weekends and holidays. It is thought to be exaggerated by disruptive things like phones and social networks that encourage people to stay up and follow the news, and it is thought to affect a vast proportion of the population.

Usually, people are forced to wake up much earlier than their biological clock would suggest, as they get up for work. At the weekends, people will often move back again, going to sleep later and making up for it with lie-ins in the morning.

Now a new study has found that appears to be causing "social jet lag", where people are disrupting their sleep pattern between the week and the weekend.

The new research came from a study that looked at the Twitter activity of more than 246,000 users from 2012 to 2013. Those tweets were tagged with geographical location, allowing researchers to use them to understand when people were going to sleep and waking up.

It found that people across the US seemed to sleep in and tweet later during times that saw large amounts of holidays. Previously, scientists had suspected that social jet lag might change with the seasons and the amount of daylight – and while it does differ through the year, that appears to be more a consequence of the way people's social schedules change, rather than anything seasonal in itself.

"We started the study expecting it to be a solar or seasonal effect – that your internal clock will shift in the summer and that will lead to decreases in social jet lag," said Aaron Dinner, professor of chemistry and one of the study's senior authors. "But in fact, that's not what we found at all. People get up later on weekdays in the summer because their social constraints are relaxed. Weekend behaviour – and presumably a person's biological clock – does not change much over the year in most counties."

The researchers also found that the data about sleep correlated with obesity rates: places that tweeted until later also saw higher rates of obesity. They also correlated with sleep data taken from more traditional studies.

"I was impressed that so much could be learned from this purely public data set that was not at all intended to tell you about sleep," said Michael Rust, associate professor of molecular genetics, cell biology and physics and the study's other senior author. "In fact, we could rediscover things like the correlation with obesity or levels of social jet lag based on time zone that were found in other studies where people designed surveys to ask about sleep directly."