Social Jet Lag and Nighttime Fasting: Surprising Sleep Research [And awkward dancing]

by Charlotte on May 20, 2012 · 19 comments


If stick figures had hair, this would so be me. And yes, there is video of my awkward dancing but thankfully it has not seen the light of Facebook. Yet. 

My neck hurts so bad I can’t even touch my chin to my chest. No I don’t have meningitis. I have something worse, something that I haven’t had since college: I have hair-flipping DOMS. This weekend my gorgeous friend (and Turbokick buddy) Lindsey got married and I danced so much at her reception that I pitted out my dress that was not only two layers of skin-tight satin but also covered in gold lace. Hot + hawt = hot mess. And me being my awkward un-sexy self, apparently I figured the best way to “dance” was to flip my hair around like I was at a Queensryche concert. No worries though: unlike my high school self, I did it ironically so I was totes cool.

After all the singing/crying/cake eating/laughing/dancing/throwing pieces of the table centerpieces at people (don’t ask)/wedded-blissedness was over, I finally collapsed in bed about 3:30 a.m. Back in the day (get off my lawn!) that used to be de rigueur but I haven’t stayed up that late without a tiny person instigating it in forever. It threw me off. And not just my neck. All day I’ve felt tired, cranky, spacey and extra hungry. And being LDS, I did all that awful dancing stone-cold sober so I can’t even blame a hangover. According to new research, what I really have is a sleep-over. And not the fun kind where you fork people’s lawns and saran-wrap their car doors shut (just me?).

German researchers discovered that people who have the biggest gap between their weekday and weekend bedtimes suffer from “social jet lag” — described by lead researcher Till Roenneberg, Ph.D., as “the discrepancy between what our body clock wants us to do and what our social clock wants us to do.” And not only does it make you feel crappy the next day, but it can harm your health.

“In a new study published today in the journal Current Biology, Roenneberg and his colleagues surveyed the sleep habits of more than 65,000 adults and found that people with different weekday and weekend sleep schedules had triple the odds of being overweight.

What’s more, the body mass index (BMI) of overweight people tended to rise as the gap between their weekday and weekend “time zones” widened.

The findings echo previous research linking higher BMI to sleep deprivation and irregular sleep schedules. In particular, numerous studies have found an increased risk of obesity — as well as chronic diseases such as diabetes — among shift workers.”

This isn’t the only interesting sleep research to come out this weekend. A new California study published in the journal Cell Metabolism (scintillating!) reports that mice – like people! except…not! — “Even though they ate a high-fat diet, the mice who wrapped up their eating day early and were forced to fast for 16 hours [over night] were lean — almost as lean as mice in a control group who ate regular chow. But the mice who noshed on high-fat chow around the clock became obese, even though they consumed the same amount of fat and calories as their counterparts on the time-restricted diet.”

But wait, it gets weirder! “The obese mice developed high cholesterol, high blood sugar, fatty liver disease and metabolic problems. The mice who ate fatty food but were forced to fast showed hardly any signs of inflammation or liver disease, and their cholesterol and blood sugar levels were virtually indistinguishable from those of mice who ate regular chow. When put on an exercise wheel, they showed the most endurance and the best motor control of all the animals in the study.” [emphasis mine] What the what?!

Right now I’m seriously regretting that wedding cake and popcorn at 11 p.m. last night.  (But seriously how delish is wedding cake and popcorn together??)

Researchers explain that “the brain and the body’s digestive machinery need to take a break from managing incoming fuel; otherwise, we may be working ourselves into a state of metabolic exhaustion.” The health gains in the fasting mice echo all the great research that’s been coming out lately about intermittent fasting (a practice I love).

Caveat alert! Before you get all excited and limit yourself to an 8-hour food window thereby making yourself “that guy” at all future evening social functions, the researchers point out that mice are, well, mice. And not only that but mice are naturally nocturnal. Says one particularly abject obesity researcher, “I hope it’s true, but I doubt it.” Referring to the mini-meals for a better metabolism concept, another adds that “This one study cannot tell us that this science is wrong.”

Yet it might make sense for humans too. For most of our history people generally ate only in the daytime. With little or no light after sunset party-poopers, er, people just went to bed. Lead researcher Satchidananda Panda point out that today “our social life starts at sunset. Family time starts at the evening. So essentially, we have increased our eating time in the last 40 to 50 years.” It makes logical sense, no? Plus, as Panda points out, it’s way easier than counting calories and nighttime snacks generally aren’t salmon and spinach anyhow so it can’t hurt to give it a go.

All of this made me remember my interview with Lifetime Fitness‘ weight loss specialist, Darryl Bushard, a few weeks ago. “Sleep is the #1 defense we have against stress.” He encouraged me to be in bed no later than 10 p.m. — “every hour of sleep before midnight is twice as restorative” — including a 1-hour technology detox before hitting the sack. (Double fail – it’s 11 p.m. right now and I still have one more article to write tonight.) My trainer Steve Toms agrees, noting that since implementing Bushard’s suggestions he’s slept better and woke up more refreshed than he has in years.

The verdict seems pretty clear: getting enough sleep at the right time and in the right way is one of the most important things we can do for our mental and physical health. Plus, it’s also one of the factors most under our control. So why is it so hard to just do it??

Any of you mastered the art of going to bed on time? Were you as surprised as I was by the overnight-fasting mice study? Anyone else dance by randomly flailing and flipping their hair??

{ 19 comments… read them below or add one }

Alyssa (azusmom) May 20, 2012 at 11:39 pm

My hair-flipping days are over, methinks. At just-shy-of-43, my head & neck just can’t take it anymore.
I DO find that going to bed after 10:00 these days pretty much messes me up the next day. (Unfortunately, “Sherlock” starts at 9 on Sunday nights and runs for at least 90 minutes, so Mondays are a bit rough.)
I do believe I shall stop eating when the sun is down. Couldn’t hurt, right?

P.S., A sore neck is, IMHO, a small price to pay for all the fun you had! ;)


Terri May 21, 2012 at 1:16 am

I always read research like this with envy. I am a chronic long-term insomniac. I generally can’t get to sleep to save my life several times a week. It is cyclic and yes I always put on weight (even without eating more calories) when I’m only sleeping a couple of nights per week, so I think the mice to human correlation may not be so far out.

I just wish I could start sleeping to see if the weight drops off :)


Sigga May 21, 2012 at 4:34 am

Im naturally a night owl. I basically never feel awake before 10am no matter when I actually got up and if left to my own devices I’ll go to bed at around 1-2am.

If completely left without an outside enforced schedule (like what happened when I was writing my dissertation ages ago) I ended up with a completely turned around day where I’d go to sleep at 6am and then wake up at 2pm-ish. I spent almost 2 months living like that. Not too keen to repeat that experiment though.

Night owl and morning lark type personalities do exist and I’m always a bit wary of studies that are all about go to sleep before midnight etc. that don’t take that into account at all.

It also bothers me when people see being a night owl as a big moral failing, it’s not, it’s just a differently wired bodyclock. Having a hard time getting up in the morning and then being very alert in the late afternoon/evening is not that much different from getting up easily and then getting tired quicker in terms of productive work hours etc.

I’ve done experiments in forcing myself into being more of a morning person but basically no matter when I wake up Im not actually feeling awake before 10am so if I am at work at 8am that just means 2 hours of zombie time at work vs 30min (I normally start at 9:30).


Abby May 21, 2012 at 11:53 am

“It also bothers me when people see being a night owl as a big moral failing, it’s not, it’s just a differently wired bodyclock.” Yes! Thank you! I’m exactly the same way. I agree, if you’ve studied chronobiology at all you know that people aren’t all the same so it’d be interesting to see some sleep studies like these that include that variable.


sara-hare May 22, 2012 at 11:37 am

I agree wholeheartedly, and yes, it is so aggravating when morning people feel they’re morally superior for being wired differently.


Miz May 21, 2012 at 5:28 am

oooh yay!!! im not into crossfit I dont do MMA :) but I do rock the sleep and the sleep routine.


Naomi/Dragonmamma May 21, 2012 at 6:42 am

The old diet ploy of “don’t eat after 6pm” has always worked well for me. Conversely: Eating late puts on the pounds, even if it’s the same amount of food. The occasional skipping of dinner and not eating until late the next morning leaves me feeling light and energetic the next day.


Laura May 21, 2012 at 7:02 am

Panda points out, it’s way easier than counting calories and nighttime snacks generally aren’t salmon and spinach anyhow so it can’t hurt to give it a go.


Amber May 21, 2012 at 10:34 am

How interesting! I’ve applied a couple of these principals just by listening to my body. I go to bed on time and get up within an hr of the same time daily because I have chronic fatigue issues on top of early rising kidlets. I try to eat dinner by 4pm because I get tummy aches that mess with my sleep if I eat later. And I don’t eat again until 7am the next day when my kids get breakfast. I found when I let myself get out of the habit, I slowly start gaining weight until the stomach aches force me to be strict about it again and I lose it!


Quix May 21, 2012 at 10:56 am

I used to be a huge night owl. Huge. Like, I’d really rather sleep my 8 hours between 4am and noon (or later). Life was perfect when I got a 1-9pm job. Now, I find I can rarely sleep past 8:30 or 9 even without an alarm no matter what – case in point – Saturday night we went out, I was up and drinking until 2:30 and BAM! up at 9 and awake.

Due to my schedule, sometimes I can’t eat dinner until 2 hours before I go to bed on weekdays (work + workout sometimes = 8 or 8:30 before I’m done, and healthy dinners don’t cook themselves) – I’ve tried to shift to doing like 4 meals a day (small-ish 200-300 cal breakfast, sizable lunch, “linner” about the same size as breakfast, and a smaller dinner) because I found a) I can graze a full meal of calories without getting full if I just snack (even healthy stuff) and b) big dinners were making me feel bloaty and full, to the point where I probably weigh my least right before LUNCH not in the AM.


Patricia May 21, 2012 at 11:22 am

I’m pretty much incapable of staying up past 10:00! I’m asleep on the couch if I’m not up in bed. My “alarm clock” children are usually up by 6:30 and Mama needs her 8 hours! Even before the kids, once I got into a routine of being up by 7 for work, I could barely sleep in on weekends and was always the one who wanted to call it a night early.


Dr. J May 21, 2012 at 11:56 am

That mouse study supports eating warrior style, which I have been doing for many years!

Now I know why :-)


caryesings May 21, 2012 at 1:14 pm

Ok, during our sleep-overs we’d decorate the trees and shrubs in the yards of boys we liked with toilet paper. What the heck is “fork people’s lawns”?


Charlotte May 21, 2012 at 4:10 pm

I’m rather skeptical of the before-midnight/after-midnight distinction. Surely it rather depends on what time you’re getting up? Or if the theory involves hours of daylight, shouldn’t it take account of the fact that sunrise and sunset are going to be at different times depending on what time of year it is and where on the Earth’s surface you happen to be? Not to mention daylight saving.

Right now, at 10pm local time, it’s not yet dark here. Going to bed now would feel all wrong – I’m eating dinner as I type! To say nothing of the fact that that would have me awake at 5am, and that would be even wronger.


jbunny May 21, 2012 at 5:52 pm

I know it’s so bad, but I love going to be on a full stomach! It just feels so cozy and makes me sleep better. Guess I better learn a lesson from the mice!


Jody - Fit at 54 May 21, 2012 at 7:23 pm

“Interesting”!!! :-) My prob – a high density area. A old town home with windows that act like they are open when they are closed so very very very noisy all the time. Barking dogs, cars, doors slamming & just too many things like this to get good sleep.


SeeAlliRun May 21, 2012 at 8:28 pm

This study doesn’t surprise me. When I have sleepless nights (which happens quite often), I usually feel like I’ve been on a bender the night before minus the puking part. I do go to bed early, but I have a hard time “shutting down”.


Casey Kay May 21, 2012 at 10:59 pm

You are not alone in the random flailing dancing. It’s why I generally avoid dancing in public.

I have found that if I get to sleep between 10:30 and 11:30, depending on what I’ve done during the day, I’m usually awake a few minutes before my alarm goes off at 6:30. Then again, I’m only 22 and I’ve read somewhere that between about the age of 13 to the age of 26 or so people naturally tend to lean more toward the nocturnal side. I have no clue where I read that, so I’m not sure how true it is.


Serena May 22, 2012 at 8:52 am

Chaarrr!! Were we hair flipping together?!! I was full body turning on Sunday too!! I wouldn’t know because said move creates such a tornado of long dark hair around me its a true “blackout” ;-) Soooo much fun though! And I have been known to hair flip often on a night out, so much so that when I tell people I am stretching my neck…they get it!! hahah!


Leave a Comment

Previous post:

Next post: