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Study: Exposure To Morning Sunlight Helps Managing Weight
jones_supa (887896) writes "A new Northwestern Medicine study reports the timing, intensity and duration of your light exposure during the day is linked to your weight — the first time this has been shown. People who had most of their daily exposure to even moderately bright light in the morning had a significantly lower body mass index (BMI) than those who had most of their light exposure later in the day, the study found. It accounted for about 20 percent of a person's BMI and was independent of an individual's physical activity level, caloric intake, sleep timing, age or season. About 20 to 30 minutes of morning light is enough to affect BMI. The senior author Phyllis C. Zee rationalizes this by saying that light is the most potent agent to synchronize your internal body clock that regulates circadian rhythms, which in turn also regulate energy balance. The study was small and short. It included 54 participants (26 males, 28 females), an average age of 30. They wore a wrist actigraphy monitor that measured their light exposure and sleep parameters for seven days in normal-living conditions. Their caloric intake was determined from seven days of food logs. The study was published April 2 in the journal PLOS ONE. Giovanni Santostasi, a research fellow in neurology at Feinberg, is a co-lead author."
Is this caused by Vitamin D perhaps? It would be interesting to compare to people on supplements.
Here in Edmonton, Canada, my family Dr. was participating in a study where her patients were tested to Vitamin D. I ended up having to take 2000 IU a day. Not that I don't get outside; during about six months of the year you won't see any daylight from 5 pm to 9 am.
Could it be that the fat people are just lazy and get up later, and don't get outside early. Maybe fat causes people to get less light in the AM. See the problem with the headline?
as the summary points out, it was only for 7 days with 54 people who used wrist mounted light sensors & 'food logs' but it's definitely worth a look
sunlight in the morning has all kinds of physiological benefits...IIRC recently it was linked to higher immune function
Thank you Dave Raggett
"[The study] included 54 participants (26 males, 28 females)". No conclusions should be drawn from a study this small. Interesting as it may be to speculate.
... Look at the overweight+ people in Hawaii. And we live in the sun virtually year round!
When you want a computer system that works, just choose Linux. When you want a computer system that works, just, choose
Seems like the sample size is too small. Or the wrong sample. I'd like to hear more, but there is not much here.
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Maybe it is evening/night people having their natural sleep schedules disrupted in our industrialized society that contributes to a higher BMI.
AFAIK, morning sun has essentially the same spectrum as evening sun (slightly red due to the longer path through the atmosphere than at noon), and the same angle of incidence, so morning sun should have no different intrinsic effect than evening sun, if the rest of the day is spent in artificial light.
Sounds like a VERY poorly controlled experiment.
Depression is correlated with sunlight exposure. Depression is correlated with weight gain.
"Early to bed and early to rise make a man healthy, wealthy and wise".
http://books.google.com/books?...
You are welcome on my lawn.
Yes I do get to see the sun rise at this time of the year, as I walk home from work.
(I work Nights you insensitive clods)
That is, "We did a tiny study for a ridiculously short amount of time without anything like controls or double blindedness and found that exposure to morning light accounts for reductions of 20% of BMI at a statistically significant level.
This could be true only if the lights one turned on when getting up "early" were frickin' laser beams attached to sharks that lopped of a major limb and ate it.
April Fool's day was Tuesday. Why post this now?
rgb
Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
Early to bed and early to rise, makes a man healthy, wealthy, and wise.
I don't know about healthy. But late to bed, late to rise, seems to make you more intelligent and wealthier That study looked at 1000 people, rather than 54. If both studies are accurate, it looks like you can be smart, fat, and rich, or healthy, poor and stupid.
Early to rise and early to bed makes a man healthy, wealthy, and dead.
Eww. I don't like that stuff! I have blackout curtains on my bedroom windows to keep it from finding me.
*Looks down at ginormo-gut*
Hmm.
NAH! I like sleeping late!
Chas - The one, the only.
THANK GOD!!!
From the Federal Bureau of Get Your Ass Out Of Bed and Into Some Running Shoes. Snark aside, I prefer to get to work early, be home by 4, and do my 45 minute bike ride then. Although I did enjoy the few years I could bike to work.
The other problem is lack of correlation for this hypothesis. There are large numbers of people whose work shifts that have them awakening at night to work during the night. If this study's conclusion is correct then the vast majority of these people should have a very high BMI, and the effects of working such shifts would have been noticed decades ago.
Then there are people at the high latitudes who have months of very reduced sunlight, and thus wake up in the dark for weeks on end. Again, do we see the same correlation there? This type of thing should be easy to study in places like the Amundsen–Scott South Pole Station, where those that stay over winter experience little sunlight for a few months non-stop.
Better known as 318230.
Younger people are generally skinnier
Not really. Childhood obesity is an epidemic in the USA.
and sleep in.
Yep. And with all the butthurt over moving high school starting times back, we'll have some good data.
Have gnu, will travel.
Is exposure just a general "bathing" in sunlight? Is exposure light entering one's eyes and providing stimulation?
Does this have anything to do with the fact that I have always had a very high metabolism yet my sleep patterns rarely follow a daily/hourly routine. I do not wake/go to bed at the same time every day. I am generally awake for 18 hours, then sleep for 8, so I sort of have a 26 hour day, which, of course, causes a number of other problems, but hey, it is what it is.
Someone flopped a steamer in the gene pool.
The early bird catches the worm. The early worm gets eaten.
The early bird catches the worm. The early worm gets eaten.
The second mouse gets the cheese.
It is a miracle that curiosity survives formal education. - Einstein
I guess this is why all the people living in Nordic Countries are obese.
First they tell us that dark chocolate is good for us because of the antioxidants and that it reduces the amount of fat that your body adsorbs from other foods.
http://www.scientificamerican....
http://www.medicalnewstoday.co...
Then they tell us that whole milk, cheese, etc. keeps us leaner
http://www.npr.org/blogs/thesa...
Now bathing in sunlight (don't forget the sunscreen) will help us manage our weight.
So, I guess this means that eating dark chocolate, chasing it down with whole milk, while sitting in the sun and reading (good thing I own a Kindle) will help me get rid of those unwanted pounds... Ahhh... This IS the life.... (grin)
In northern countries a day in the winter is short, in southern countries it is longer. As we do not notice big difference between body weight in north and south, what is morning exactly? Is it the time just after you wake up and turn on light? Or is it time when the Sun rises? Or what?
Call me cynical, but I'm just suspicious that people who get up and run around in the morning have a lower BMI because they get up and run around in the morning. The whole sunlight thing, that's just a coincidental (mis)feature of morning. By which I'm sure you can intuit my BMI range. :)
I have often remarked to my SO that the primary fault with mornings is that they don't wait until at least noon to begin.
I've fallen off your lawn, and I can't get up.
A few years ago I started using a couple plug strips each with 6 'daylight' florescent bulbs during the winter (in Seattle).
Gazing into them for the 10-20 minutes of groggy 'just woke up' time gives me, personally, a boost through the whole day; followed by being able to fall asleep at a reasonable hour in the evening.
ymmv, but if you suffer from chronic sleep schedule drift, I would recommend trying it. You don't need an expensive 'lamp system' Just be sure to get the blue-ish 'daylight' bulbs, not the reddish 'warm' bulbs.
The reason this happens is because there is a bundle of neurons in the hypothalamus called the suprachiasmatic nucleus. These neurons receive blue light from your eyes to precisely control sleep/wake rhythms. These neurons feed directly into the arcuate nucleus, the part of the hypothalamus that senses hormones and regulates your metabolism, hunger, and alertness.
Source: Im a neuro-endocrinology researcher. Im also working on an open source genomics experiment to study this stuff. Join if you have genome and fitbit data! www.infino.me
Perhaps an as yet unknown agent contributes to obesity and makes it less likely for its sufferers to be up early enough to get some early morning sunshine. The lack of exposure at that time of day doesn't necessarily cause the obesity; nor does obesity directly prevent exposure to early bright light. They both could well spring from some other mechanism.
Early to rise, early to bed, makes a man healthy, but socially dead.
Obviously, I am once again an exception. I take the bike to work and I do it most of the week during spring, summer and fall. I have 30+ minutes of exposure to light in the morning. I'm still a fat fuck. That despite balanced meals, carbohydrate consciousness and aforementioned 3 to six hours of physical exercise per week.
So frankly, fuck all those weight 'scientists'.
Your stomach growls because it's moving a mixture of solids and liquids inside a (somewhat) sealed system. Fluids flow down, gasses bubble up, and the walls of the container are flexible enough to make the body a sounding board. Those sounds are even a great diagnostic indicator (their absence demonstrates that there is some sort of gastrointestinal problem).
So you're Bajoran?
Early to bed and early to rise
Makes a man or woman
Miss out on the nightlife
RIP Mark Sandman.
This comment is just as redundant as the request to the editors to throw garbage like this into the waste-bin instead of treading us to it and waste even more bits.
Correlation is no causation and here Northwestern Medicine ought to pay back the funding and instead be supplied with brown bags for over their heads: "This bag covers gently the red face of someone who bungled it on science"
Yep, this case could make it into a new standard textbook example why correlation is obviously no causation. It is so bloody obvious that even a /.-editor can be expected to understand it. The assumption is really and seriously ridiculous.
Any remnant of common sense teaches any low-IQ person that the light can not have any influence of BMI; be it morning light or late afternoon light. Common sense dictates that the early bird simply favours a lifestyle different from the average late riser.
Nothing to be seen here: You may move on happily! - Northwestern Medicine has actually confirmed that BMI depends to a large extends on someone's lifestyle.
Early to bed and early to rise, makes a man healthy, wealthy, and wise.
The early bird catches the worm. Thus we worms nap as cats and gain their protection. Being early to rise is for the birds we're against.
Seriously? How is that even statistically significant?
Never mind.
For the rest your arguments, especially in the second sentence, are bollocks.
"The likes of Facebook and WhatsApp are free to those whose privacy is of zero value."
AFAIK, morning sun has essentially the same spectrum as evening sun
No it doesn't. The authors address the differences in the spectrum in the third paragraph of the Discussion section of the study.
Head outside at 9 am for a cigarette break?
It's for your health.
For all those yelling "This is clearly bad science", it's not. The summary is not the paper. The paper notes that there is a correlation between a certain pattern of light exposure and BMI in their sample group. The hard part about the paper is the models they used to capture temporal patterns of light exposure and determining if they are valid. The paper does discuss the model in detail and notes that there are issues that it fails to address.
The rest of the analysis is fairly accepted sensitivity analysis, which factors in the sample size. Also, the paper notes that there have been other studies in animals that have linked light exposure to changes in metabolism, so there is a potential for the mechanism to be causative. But the paper clearly notes in the summary that directionality of the found relationship can't be determined from this study. In other words, the paper just suggests more avenues of research into the links between light exposure, sleep rhythms and metabolism and suggests that the temporal aspects of exposure could play a role.
Finally, the intervention that it suggests is fairly harmless. If people start getting more sun in the morning, that's probably okay overall.
Does anyone else think the same as me when they see "food logs"?
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
My mistake - I'd assumed that a stomach growling was a digestive noise? I thought the stomach was part of the digestive system.