DO you stay up late and enjoy long lie-ins at weekends then struggle to go back to work early on a Monday morning?
You could be suffering from social jet lag – a shift in your internal body clock.
GettySocial jet lag is thought to affect up to 40 per cent of Brits[/caption]
The phenomenon occurs when you go to sleep and wake up at different times during the week compared to Saturdays and Sundays.
This disturbs your circadian rhythm – an in-built, 24-hour system which signals to your body when it’s time to go to bed – much like traditional traveller’s jet lag when shifting between two time zones.
A new study by King’s College London, published in the European Journal of Nutrition, found that even a 90-minute difference in the midpoint of your night’s slumber (halfway between nodding off and waking up) over the course of a normal week was enough to alter the bacteria in the gut.
This can lead to weight gain, poor mental health, heart problems and diabetes, scientists say.
Kate Bermingham, study author and senior nutrition scientist at health science company ZOE, said: “[Social jet lag] can encourage microbiota species which have unfavourable associations with your health.”
Scientists analysed the sleep, blood, stools, gut microbiome, glucose levels and diet of almost 1,000 participants.
Those who had social jet lag (16 per cent) were more likely to scoff crisps, chips and sugary drinks, and less fruit and nuts.
This supports previous research which shows sufferers also consume less fibre than those with consistent sleeping times.
“Poor quality sleep impacts choices – and people crave higher carb or sugary foods,” Dr Bermingham said.
The team found three out of the six microbiota species more common in those with social jet lag are linked to poor nutrition, indicators of obesity, heart attacks and stroke.
While only 16 per cent of participants were categorised as suffering from social jet lag, it is thought to affect more than 40 per cent of the population.
The most common signs, according to sleep tracking app SleepCycle, include:
Intense morning grogginessDaytime sleepinessInability to focus on tasksTrouble falling asleepReduced emotional wellbeing Headaches Constipation and/or diarrhoea
Thankfully, there are some things you can do to reduce your risk.
1. Stay consistent
First and foremost is going to bed and waking up around the same time.
Dr Sarah Berry, chief scientist at ZOE, said: “Maintaining regular sleep patterns, so when we go to bed and when we wake each day, is an easily adjustable lifestyle behaviour we can all do, that may impact your health via your gut microbiome for the better.”
It can be difficult to stick to an exact schedule, but experts suggest trying to limit yourself to a 30- to 60-minute difference tops.
2. Keep hygiene in check
It’s also vital to practice good sleep hygiene, or habits, SleepCycle recommends.
That means keeping your bedroom free from distractions like phones, laptops and TVs – and not using them for an hour before bed.
The temperature should also be nice and cool where you sleep, and it should be dark.
And it’s best to avoid large meals, caffeine and alcohol before you hit the hay, according to the NHS.
3. Get moving
Another way to get a better night’s kip and reset your body clock is through exercise, the NHS says.
Studies show physical activity during the day can help you sleep – but vigorous workouts should not be carried out within three hours of going to bed.
4. See the sun
Finally, get outside if you can – but not too late.
The NHS says: “Morning and early afternoon light exposure will help you to maintain a healthy sleep-wake cycle.
“Too much light exposure in the evening can prevent you from feeling sleepy.”