२६ जानेवारी, २०१४

"Is the rise of central heating a contributor to the obesity epidemic?"

Asks Instapundit, linking to Stephan Guyenet, a neurobiologist, who describes some biological processes related to brown fat (fat with lots of mitochondria) and thermogenesis (activated by the brain). Maybe the lack of exposure to cold air is keeping the brain from activating the brown fat? Guyenet describes a study:
The protocol involved exposing people to 60 F (15-16 C) air for two hours on day 1, four hours on day 2, and six hours on days 3-10. Although I assume they were lightly clothed, this is a pretty mild cold exposure.
Here in Wisconsin, where I'm only hoping for temperatures above zero and wind chills above the negative single digits, we set the thermostat at 60° so it's interesting to hear this called "pretty mild cold exposure."
The second study went further....
Egad!
.... using a longer cold exposure protocol to investigate changes in fat mass among people with low brown fat activity at baseline....  Researchers exposed volunteers to 63 F (17 C) air for two hours a day over a six-week period
63° for 2 hours! 63° is what I turn the temperature up to sometimes when I'm feeling fragile.
As in the previous study, they observed an increase in brown fat activity with cold training...
Cold training! Who are these people?
... and they found that calorie expenditure was higher when subjects were in the 'cold' air.  After six weeks of training, body fat mass had declined by about 5 percent. 
Aw, come on. And these subjects were already lean! What were they doing before the study that this experiment constituted a variation?

Guyenet enthuses:
Think about it: two hours a day at 63 degrees F.  
Assuming that's a lowering of the temperature. (It would be in summer. Should we power up the A/C? Or just go swimming in unwarm water? (But I heard swimming causes the body to respond with a layer of fat.))
That would seem downright luxurious to a person 100 years ago in winter in almost any temperate climate.  
A person 100 years ago! Here I am, right here,  your person from 1914.
Today, most people keep their central heat closer to 70 F in winter, apparently eliminating a major source of passive calorie burning.
If we put the heat that high in winter, the air would be stifling and we'd be lethargic and (probably) plagued with sinus infections. Now, it turns out that Guyenet is himself an advocate of keeping the temperature low, and it's because he's an environmentalist:
I use less heat because I'm an environmentalist, and because I feel that humans are meant to experience cold stress sometimes just as we're meant to experience exercise stress.  The winters aren't particularly cold in Seattle, and I leach heat from downstairs, but the temperature nevertheless fluctuates between 45 and 55 F for several months of winter, with occasional excursions below 40 F.
So lowering the thermostat is something Guyenet wants you to do anyway, and it's something he (and I) are already doing whether it burns more calories or not.

I've long thought that to burn more calories you ought to drink more ice water (which would include tap water on a day like today). I don't know about the hypothalamus activating the mitochondria, but isn't it obvious that your body is going to have to expend calories to warm up anything cold you put in. Now, I'm distracted by the thought of a lucrative business manufacturing smooth metal devices that fit comfortably into various bodily orifices. You chill them to some perfectly comfortably cool, safe temperature,  then insert them until they warm up. Calories burned. Or, possibly, brown fat activated. Maybe the effect is greater than the expenditure of energy heating them up, if those studies mean what they supposedly mean.

I'm concerned that there's a blubber-up reaction to cold in the long term. Fat protects you from the cold.  Take a look at the walrus. Nature did not evolve us to freeze to death (or to starve from over-burning our fat reserves). Our ancestors survived cold and privation to give us bodies that make us drift toward resemblance to the walrus.

ADDED: Meade read this aloud — helping me proofread — and groaned at the expression "Nature did not evolve us to...."

I protested.  "This is not formal writing. It's an invention, meant to humorously resemble 'God did not create us....' I'm personifying Nature."

Meade doesn't really answer, but I type out my quote and read that to Meade to extract a response and he says "I like it" and gives me permission to quote this colloquy.

Another morning in the north, pre-dawn, getting the blogging started at Meadhouse.

३० टिप्पण्या:

Ron म्हणाले...

"blubber-up" sounds like a really disgusting soda.

Will 1914 Althouse be visiting Archduke Ferdinand? If so, please don't start WWI by mistake, though your Madison paper will probably blame you anyway.

David Regier म्हणाले...

How about the decline in smoking?

Meade म्हणाले...

Wilford is the walrus. I am the carpenter. Goo goo g' joob it's cold! Here - I'll put on another log.

Ann Althouse म्हणाले...

Meade's trying to log on.

Ann Althouse म्हणाले...

Reading that, Meade says: "I am the carpenter. If only you were a lady."

Bob R म्हणाले...

Guyenet says he is an "environmentalist" so the fact that he uses pseudo science to reinforce his religious beliefs is par for the course. I guess that if his theory is true it takes about 60 years for the increase in central heating to cause an increase in obesity.

Althouse and Meade are lucky to have (apparently) similar temperature preferences. I like it several degrees colder than my wife. We have to split the difference and wear contrasting layers of clothing.

Ann Althouse म्हणाले...

I say: "People are going to have to get 3 references: 'I Am the Walrus,' 'The Walrus and the Carpenter,' and 'If I Were a Carpenter,' which I think at this point is for most people pretty obscure."

And Meade says: "There going to also have to get this next reference: 'We've only just begun.'"

Which works as a warning: Don't lose too much weight!

The walrus is still around, and the superstar disappeared into thin air long ago.

Ann Althouse म्हणाले...

"Althouse and Meade are lucky to have (apparently) similar temperature preferences. I like it several degrees colder than my wife. We have to split the difference and wear contrasting layers of clothing."

If the temperature preference relates to a need to breathe cool air, the clothing doesn't help. I think, within reason, the person who needs cooler air should win. Give her some nice thick long sweaters and so forth.

mesquito म्हणाले...

My mother, when she was a child in Norway, would visit grandma on a coastal island. They would spend several weeks each summer cutting peat and carrying it strapped to their backs in large baskets, several miles back to the house. Ma remembers that grandma would not let her hands be idle during these walks, so they knitted.

I have no idea how they set their thermostats.

David53 म्हणाले...

I would be fine with leaving the thermostat at 60 if my hands didn't get so cold. Poor circulation I guess.

traditionalguy म्हणाले...

Wait until the Federal Death Panels hear about this. By then the Federal wifi controlled thermostats will have been installed.

The National Temperature Controller, likely named Bloomberg, will have a ball.

Seriously, the walk about in the cold weather for 2 hours a day should be implemented, starting with Siberians.

Ann Althouse म्हणाले...

Have a mug of hot liquid and hold onto it as needed.

You don't have to drink it unless you want, and you can reboost the heat in the microwave from time to time.

rhhardin म्हणाले...

Regardlss of indoor temperature, owners of heat pumps are in for a lesson in thermodynamics when the bill comes this month.

Wince म्हणाले...

I don't know about the hypothalamus activating the mitochondria...

Is it dyslexic to think he sounds more like the mite-be-a-walrus activating the hypochondria?

MayBee म्हणाले...

India and SE Asia tell me this theory is bunk.

MayBee म्हणाले...

I also think the sinus infection and warm air theory is also probably bunk.

Paco Wové म्हणाले...

Chez Althouse and Casa de Paco have identical thermostatic regimes. Interesting. (Well, not really...)
En la casa we let the winter night temperatures drop to about 52°F or so, which we find helpful for sleep. And because we're cheap miserly bastards.

Roger Sweeny म्हणाले...

Here in the Boston suburbs, I don't know anyone who considers 70 degrees "stifling." We keep our place at 64 but consider it good manners to put the thermostat up before company comes.

MaxedOutMama म्हणाले...

What's ridiculous about this is that A) exposure to cold with calorie restriction and low light will trigger a thyroid-mediated downshift in metabolism for many people, meaning you have to move A LOT to prevent your body's adaptive mechanisms from kicking in to save you from its biologically-determined fear of starvation, and B) most people don't heat their houses to anywhere near 70 in the winter. They can no longer afford it. 65 is becoming relatively rare.

Nor are people cooling their houses in heat the way they used to. The average American is exposed to higher closed-environment temperature ranges than a decade ago.

That is real - you can see it in utility and fuel consumption figures.

Butter consumption is rising though, probably because people are so effing cold and you need a higher fat content in your diet to deal with that.

People are mostly fat because they follow the USDA food pyramid, eat low-fat foods with a lot of sugar, and don't exercise nearly enough. The human body is designed to move for a good six hours a day and to conserve calories when it senses a poor-quality diet!!!

Only in Seattle could a bat-shit crazy faddist believe that most American households are heated to about 70 in winter. How idiotic.

Lindsey म्हणाले...

"Now, I'm distracted by the thought of a lucrative business manufacturing smooth metal devices that fit comfortably into various bodily orifices. You chill them to some perfectly comfortably cool, safe temperature, then insert them until they warm up. "


This is otherwise known as a speculum.

अनामित म्हणाले...

I read that article that proposed heating as the explanation for obesity. Then I read this one:

http://www.nytimes.com/2004/02/06/health/06CARB.html

Women consume, on average, >300 calories more per day, men > 150, comparing 1971 to 2000.

3500 calories = 1 pound of fat.

Women are eating enough to gain >2 lbs per month. Men, over 1 lb per month.

It's not the heating, it's the eating.

Ann Althouse म्हणाले...

"En la casa we let the winter night temperatures drop to about 52°F or so, which we find helpful for sleep."

We were enjoying the thermostat set at 50° for sleeping until we woke up one morning after a sub-zero night to find the moisture in the furnace had frozen triggering a shutdown and we had to call in the repairman to get it going again. Now, we have to keep it warmer on the coldest nights. It can't cycle off too long or it will freeze.

Ann Althouse म्हणाले...

"It's not the heating, it's the eating."

Well, it could be both. Maybe heating increases eating.

Should be the opposite though.

MadisonMan म्हणाले...

63 in our house. When I visited Dad on Althouse's birthday (Dad's too), his apt was a torrid 75. Uncomfortable!

MadisonMan म्हणाले...

63 in our house. When I visited Dad on Althouse's birthday (Dad's too), his apt was a torrid 75. Uncomfortable!

n.n म्हणाले...
ही टिप्पणी लेखकाना हलविली आहे.
n.n म्हणाले...

It's due to the Couch Potato Syndrome caused by a preference for comfort, which is influenced by the ambient temperature. It is also caused by a dissociation of risk. In which case it is also known as the Spoiled Child Syndrome.

MySherona म्हणाले...

You guys are tough old coots. My wife and I have compromised on her 70 degree preference. Nights are programmed for 62.

My hands are cold at 70, holding hot tea doesn't doesn't help - burns the inside, outside still cold.

furious_a म्हणाले...

Would think A/C in the summer makes us fatter. Keeps us inside where it's cool instead of outside sweating off inches.

Andy Freeman म्हणाले...

> owners of heat pumps are in for a lesson in thermodynamics when the bill comes this month.

That depends on what they're using for their heat reservoir. Folks who are using deep ground won't see the same things as folks who use outside air.