Survey: Nightlights Make You Fat

An Ohio State University study found that exposure to light while you sleep can fatten you up. This is especially true if you happen to be a mouse.

The study says a group of mice that was exposed to dim light at night gained 50 percent more than another group that got to sleep in the dark.

The study suggests that the light-exposed mice ate more often — even though they didn’t eat any more than their dark-sleeping pals — and that screwed things up.

“Something about light at night was making the mice in our study want to eat at the wrong times to properly metabolize their food,” the lead author of the story said in a press release.

So as you go to sleep each night you’ll have to choose between obesity and protection from the monster that lives in your closet.

Too much light at night at night may lead to obesity, study finds [Eurekalert via BoingBoing]


Edit Your Comment

  1. jason in boston says:

    It’s not the light – it is shoveling more food (calories) than you burn off. It’s weird that the light wants you to eat more.

    Is this also true of people in Alaska or Scandinavia during their perpetual winter?

    • GuyGuidoEyesSteveDaveâ„¢ says:

      But if you read, they DIDN’T eat more. They ate the same amount, just over a different period.

    • ttw1 says:

      Another reading comprehension FAIL.

    • jason in boston says:

      I read the press release – would rather read the actual study. I’ll see if the old Ebsco would able to find it (Proceedings of the National Academy of Sciences).

      Did the mice eat the same exact amount of food in both studies as with the control group? The press release isn’t clear*. They merely say that the food intake was measured.

      *I read the 4th line quote – but would rather have either the whole quote or the reference point the researcher was referencing.

  2. Bativac says:

    I watch TV as I sleep. I set the sleep timer but it’s still on as I’m dozing off. Is this why I’m having trouble losing the 20 pounds of dead weight I’m carrying around?

    Do I want to be thin or do I want to watch Futurama reruns as I pass out?

    • TouchMyMonkey says:

      I think it has to do with the quality of sleep you get. If you aren’t sleeping well, you’re tired all day, and you’re not exercising as much. That is the point.

      • Tim says:

        That seems to be what I got out of it too. Essentially, light makes you not sleep as well.

        • RogueWarrior65 says:

          Perhaps, but what if you can’t get to sleep because it’s pitch dark and so quiet that you can hear every noise in the house?

          • aaron8301 says:

            Nobody said it had to be quiet. I sleep with a quilt over my window, and a 20″ box fan on the dresser pointing at me. Nice and dark, a little noise, and I sleep like a rock.

            Of course, the breeze from the fan helps as well, as I’m half Polar Bear.

    • Aennan says:

      I have chose the Futurama option (via Roku).

    • Copper says:

      I’ve been watching Futurama as I sleep for four years now…

  3. tedyc03 says:

    I’d be nervous about making a correlation here between light and weight gain.

    Humans tend to sleep on a clock schedule while mice follow their Circadian rhythm; give them light and you break that rhythm. And maybe I’m off base but don’t mice live underground and/or mostly in dark spaces? If it’s light it must be time to eat to a mouse.

    Lab mice are great for lots of things but I think in this case the scientists screwed up.

    • apd09 says:

      how dare you question science and scientists!

      They are trying to tell you how to live your life in a perfect vacuum immune to outside stimulus. Who cares if the child is afraid of the dark and thinks monsters live under the bed. It is your job as a parent to not give them a night light because they will become overweight. If only there was someway to counter the potential gain in weight like say removing toys from happy meals, no, that won’t work because that is still people telling you how to raise your child. Oh I got it, how about if parents once again take responsibility for their children and not let them over indulge on unhealthy snacks.
      No, no, no, science is right, don’t let the kid have a night lite just like on Sept 20 Consumerist told us science said kids are over weight because they were exposed to adenovirus 36.

    • GrayMatter says:

      Regarding circadian rhythms in humans: You have never watched a child go through adolescence. You have this nice kid who goes to bed at a decent hour; all of a sudden this same kid stays up until 2:00 am and will sleep to noon.

    • adamstew says:

      That’s essentially what the consumerist and the linked article said: “Mice exposed to a night-light didn’t eat more, they just ate at the wrong times.”

      Lab mice and humans are very similar in genome, anatomy and biology. So anything that affects mice also probably affects humans in the same way. Exposing a human to a night light would likely affect their eating habits in the same way as they affect a mouse.

      What the researchers found was that exposing mice to light at night screwed up their eating patterns. They didn’t eat more food, they just ate the food at the wrong times (i.e. when they were inactive).

      Reading the linked article, you’ll discover that the scientists did a second experiment to confirm that conclusion. They created 3 groups of mice…one control group, one group exposing mice to a night-light, and a 3rd group where they exposed the mice to a night light but also restricted their access to food to the times that they should be eating. They found that the mice exposed to a night light but only had access to food when they should have didn’t gain any weight either.

      The conclusion is pretty solid: Exposing mice to a night light screws up their eating habits which causes them to gain weight.

      This doesn’t necessarily translate directly in to people, but it does give you a solid hypothesis to build a really good experiment in people. They do these experiments on lab mice because mice and humans have very similar biology, anatomy, and genome…you can say “if this works in mice, it probably also works in humans”.

      This conclusion also meshes pretty well with just about everything that any nutritionist has ever told me: “don’t eat after 8:00pm” (or 7pm, or 9pm, or whatever depending on who you talk to).

      • Fineous K. Douchenstein says:

        My question (without having read the article) is how intense is this light they were exposed to. I can understand the body wanting to have food when the light is equivalent to daylight. Having a dim light to prevent slamming my foot painfully into an unseen object when I get up in the middle of the night to take a leak isn’t going to make me want to eat any differently than I do now.

        • apd09 says:

          that’s why you need those slippers with headlights on them. Have you seen that infomercial yet?

        • GuyGuidoEyesSteveDaveâ„¢ says:

          If you read the article, you would know. The light they were exposed to at night was 5 lux compared to 150 lux of standard light.

  4. TouchMyMonkey says:

    Wow. And I have on of these alarm clocks with really huge LCD numbers that lights up the whole room. I really do have to find the dimmer now (hoping there is one).

    • rpm773 says:

      I have a clock radio with (supposedly) 20 dimmer settings, and even on the lowest it’s too bright for me.

      Hack fix: I took a presentation slide that you can print to via an inkjet printer, made a dark slide with my favorite computer paint program, printed it, and then cut out a square and double-sided taped it to the radio.

      • BuyerOfGoods3 says:

        holy crap. I just put something over/in front of mine, like – a towel or book.

        That’s way too much effort. :)

        I like my darkness at night, too.

        • rpm773 says:

          Unfortunately, I’ve been cursed with the need to be able to turn over and see what time it is at night when I’m half asleep, so I don’t want to have to move something to see it. That’s too much effort :)

      • HogwartsProfessor says:

        I put a square of black velvet over the thing and I can flip it back to see the clock. I can still hit the snooze button through the fabric. Works pretty well.

        I have to cover my phone handset I keep in my room in case of burglars also. It shows the time on the screen even when I’m not doing anything and is almost as bright as my clock.

    • Ihaveasmartpuppy says:

      I put my eye mask over my clock display. Nothing worse than having a clock telling you it’s the middle of the night when you’re trying to sleep.

  5. Angus99 says:

    No way will I let my monster out of the closet. Wait, what are we talking about again?

  6. Mulva says:

    Tell that to my 9 year old…

    • Beeker26 says:

      You’ll just have to tell him that being eaten by a monster is much less painful than spending the rest of your life being ridiculed and scorned for being a fatty. You might also want to throw in that once he gets fat from the night light the monsters won’t want him as they only like lean young children. Monsters have to watch their figures too y’know.

  7. AngryK9 says:

    The monster that lives in my closet is too fat to chase me down, so I don’t worry about him. I probably slept with the light on as a child too.

  8. Murph1908 says:

    It was a survey that came to this conclusion?

    What’s making you fat?
    a. My metabolism
    b. My nightlight
    c. McDonalds Monopoly

    I think you mean it was a study that made this claim, as you stated in the first sentence.

  9. Santas Little Helper says:

    I work nights, 9pm-7am, and I sleep from about 8:00am – 3:30-5:30. I have definitly noticed since I started working nights I have to be much more careful about what I eat and when I eat it, otherwise, kaboom goes my waist line.

    • Oranges w/ Cheese says:

      Oddly enough, the one time I had a night job I ate like crap and lost tons of weight. At the end of that job I was thinner than I had ever been before in my life.

  10. Macgyver says:

    If they did the test on mice, and not people, it doesn’t mean anything.

    People need to stop telling other people how and what to eat. If people want to not eat healthy, let them, it’s not hurting you.
    I think some people have cacomorphobia.

  11. backinpgh says:

    I’ve seen studies that say light at night does all sorts of weird things to you, from making you gain weight to messing up your internal clock. My husband and I used to sleep with the TV on all night long and this is part of the reason why we stopped…now no tv or anything in the bedroom.

  12. smo0 says:

    This article was actually touched on YEARS ago… back in the 90s in fact. It’s not new…. and it is proven.

  13. Oranges w/ Cheese says:

    Well shit.

    I slept with a nightlight until I was like 10 :(

  14. coconutmellie says:

    As usual, this is the first thing that comes to mind when I read a headline and story like this one:

  15. eturowski says:

    “An Ohio State University study found that exposure to light while you sleep can fatten you up. This is especially true if you happen to be a mouse.”

    This is NOT what the study claims. As stated in the article, mice are nocturnal. They were not “expos[ed] to light while [they] sleep.” They were exposed to light during the time that they are normally active (in the dark), which altered their feeding patterns and metabolism in both the light and dark periods.

    RTFA, Consumerist.

  16. B says:

    Makes sense. Assuming, of course, that the light in question is a Kenny Rogers Roast Chicken sign.

  17. lanshark says:

    No wonder my poor chinchilla weighs nearly 3 lbs, what with the lights on nearly 18 hours a day. It could also be the constant grazing.

  18. redbess says:

    I have to call anecdotal shenanigans. Before I got married I had a hell of a time either staying at my weight or maintaining (fluctuated around 110) and, due to personal issues, I slept with a regular light on every night. After getting married I mellowed out and slept in the dark and, oh look, weight gain!