Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
31 Jan

Is Central Heating Related to Obesity?

Why are so many people in first-world countries so overweight? Why is metabolic syndrome so prevalent? The familiar contenders are diet and exercise – more specifically, the wrong kind of each. Both Conventional Wisdom types and nutrition nerds (myself included) agree that we’re doing something wrong in the kitchen and the gym, and that fixing that stuff could solve most of our weight (and even health) problems. Of course, that’s about all we agree on. Specific definitions of “fixing” and “that stuff” remain subjects of vociferous debate. That said, I like when we can agree on something, even if that something is just speculation about another possible factor in the obesity problem. In today’s Monday Musings we’ll take a look at one such factor.

A recent study out of the journal Obesity Reviews notes that it’s not just diet and activity levels that have changed in correlation with rising obesity numbers, but ambient temperature. To be more specific, people are heating their homes at all hours of the day, even as they sleep, and spending less time outdoors exposed to the elements. Central heating is more common, while space heaters, fireplaces, and electric heaters are less common, meaning the entire house gets and stays warm. People in developed countries exist in relative thermoneutrality: a nice 68-72 degrees F. The authors guess that with less exposure to thermal stress, we’re burning fewer calories. Our bodies have an easier time regulating our internal temperatures, and expend less energy doing so.

On the surface, their ideas might remind you of the outdated, overly-simplistic calories in, calories out model, where people are fat because they eat a few extra candies between lunch and dinner that add a few dozen calories to their daily allotment. It’s more complex than that, though. Exposure to cold is a type of stressor; to be specific, it’s a thermal stressor. Our bodies respond to stressors by adapting and (hopefully) improving, as you well know, and hypothermal stressors, like taking a cold bath, going for a swim in the middle of winter, or even letting the heat go off at night, induce the creation of brown fat. Brown fat is different from the reviled and feared “white fat” in that it keeps us warm by burning white fat. Newborns have lots of brown fat because they can’t shiver, can’t crawl (away from cold and toward warmth), and have underdeveloped central nervous systems that can’t be counted on to react quickly enough to changes in ambient temperature. It’s how they stay warm. Adults have far less brown fat, but they can develop more through exposure to cold. Furthermore, brown fat levels in adult humans are highest during winter and linked with less visceral fat and a lower BMI. If you’re subjectively cold, chances are you’re spurring the creation of new brown fat or increasing the activity of already-present brown fat.

This all seems quite reasonable, doesn’t it? I do love it when I can agree with obesity researchers.

On a different note, a quick word about that Yahoo! Shine article floating around. You know, the one telling you the eight ways carbs will make you lose weight. It’s silly and not worth a lot of typing, so I’ll make it short. The thing that jumps out at me is the author’s obsession with “Resistant Starch.” First of all, I’m not sure why it deserves repeated capitalization (maybe it’s some sort of deity?), and second, resistant starch is just another type of prebiotic whose fermentation by microbiota releases beneficial short chain fatty acids. You can get the same kind of reaction by eating other sources of soluble fiber, many of them decidedly low-carb. Think leafy greens, broccoli, berries, apples, jicama, onions, garlic, leeks, Jerusalem artichokes. And yes, if your activity levels and metabolic health permit, Primal starches are good sources of resistant starch and soluble fiber alike, but it’s not the carbs doing it. It’s the “carbs” that you literally cannot digest without your little microscopic friends’ assistance.

Can keeping central heating on really be at least somewhat responsible for the obesity epidemic? Have you ever noticed a correlation between ambient temperature and your own weight? Let me know in the comment section!

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. Oh and personally I am always freaking cold even when it’s 70 at home. wearing thermals and still having blue fingernails. By the theory that I’m burning all those extra calories TRYING to keep warm I should be a waif. NOT!
    Yes, trying to keep warm may burn a few extra calories but it’s actually those damn people who are always hot who seem to be burning the furnace extra hot and stay thinner or lose weight easier.

    fitinspite wrote on January 31st, 2011
    • Trying to keep warm by putting on a sweater and turning up the thermostat doesn’t burn any calories at all. Trying to keep warm through thermogenesis does. Leave your comfort zone, the human body is remarkably adaptable.

      Yea to Life wrote on January 31st, 2011
  2. we moved to an environment with rther flattened temps: the cold of winter hits about 40 d F, and the heat of summer — when really hot — goes to about 75 d F.

    this has been hard on us, as we like our extremes. LOL

    but, what is interesting is that our home is not heated. we have a heat pump, but there’s no central air. we rarely use this heat pump, to be honest, even in the ‘heart’ of winter. we did use it for some late evenings (turning it off before bed), and there were a few nights where we do get frost (and a fey days too) and perhaps a snow flurry.

    we love to get shivery, and we love to “burn the brown fat.” LOL

    i also love to sauna. i love to sweat it out about once a week. 😀

    zoebird wrote on January 31st, 2011
  3. Not sure if weather patterns helps or hinders my weight gain, but when my husband and I moved from Vermont to California we lost weight (mostly because we can be outside all year round without much planning of clothing). However, I used to gain weight before becoming paleo when it was cold outside because I would crave certain “hearty” foods like stews with potatoes and squash. In the summer I would crave light, colorful meals like salads or fruit smoothies.
    Again, this hasn’t been the case since switching to Paleo, but since moving to Cali, we never use the heat and we keep the house at a low of 55.

    Marissa wrote on January 31st, 2011
  4. I heat with wood, and it’s a lot of work. So if it’s not really cold, sometimes I don’t make a fire. The house stays about 55-60 degrees on a sunny day in winter. This is comfortable enough for me. Thanks for giving me another excuse not to make a fire!

    shannon wrote on January 31st, 2011

    Looks like fit people stay warmer because of better blood flow, while not-so-fit people don’t for the opposite reason.

    Also, women get colder because of a more even body fat distribution, so their extremities have less insulating fat.

    I live in the foothills in Los Angeles and it gets pretty cold at night in these old wood frame houses. I may have been a bit fitter-looking before we discovered the landlords pay the heating bill a couple of months ago…curious and curiouser!

    Jackie wrote on January 31st, 2011
  6. I would like to know if there are any bad effects of trying out Tim Ferris cold suggestions. What about cortisol levels? Would your body try and gain more fat to stay warm? What does Mark think of Tim Ferris’s thermal loading ideas.

    Allison wrote on January 31st, 2011
  7. I guess I shouldn’t complain as much about the school I work at in Japan, where we have no central heating and the classrooms are open to the elements. It is a little weird teaching English and being able to see my breath though. I guess it’s just toughening me up!

    Matthew Myers wrote on January 31st, 2011
  8. Obesity Reviews…!?

    rik wrote on January 31st, 2011
  9. I’ve been thinking a lot about the Vibram winter wear and the fact that hunter gatherer societies who resided in cold climates didn’t go barefoot, so why would barefoot winter shoes be necessary? Kind of on topic… A thought more so on topic; if we’re trying to shirk CW and eat like our evolutionary ancestors, we’d be eating one big meal at the end of the day before bed, b/c in theory, thats when the hunt would’ve been successful. After section hiking the AT, I know this to be true, if you eat before you sleep, you’re a hot sleeper, meaning, you wont freeze in the middle of the night, and vice versa. Being exposed to the elements means you have to consider your meals more, if you have the fuel, your body burns it for heat, therefore, you’re warm. Also, if you keep moving, you’re warm. Turn down your thermostat, it’ll keep you off the couch, eat a big meal before bed, you wont sleep cold. Simple, right?

    huntergirlhayden wrote on January 31st, 2011
  10. Hmmm…. when I was younger (and thinner) we did not use central heat but relied on the sun and baking when it was really cold. I also walked alot (so my kids tell me). I never had to watch our diet and we were all healthy weights: kids and adults.

    Today… I live in a desert environment and have gained weight. We use central heat and A/C. Both were new luxuries to us when we moved here.

    Winter time: 65 degrees at night, 68 to 72 degrees daytime IF we feel chilled; otherwise we keep it at 65. I do alot of gardening in winter and when I’m active I normally don’t need daytime heat indoors, even when the outdoors is in the 50’s.

    Summertime: house kept around 80 – 85 degrees (rarely down to 70 if someone feels sick). In the hottest part of summer, we find the AC necessary to sleep at night. Outdoor temps in the summer are often over 100, and don’t drop below 90 at night for a few weeks, so few folks want to be outside and remain sedentary indoors to stay cool. I’ve been blaming the hot summers as a factor in my weight gain. (I have 50 lbs to lose)

    Let you decide if that helps or not.

    SJ wrote on January 31st, 2011
  11. Thanks for the blog idea Mark!

    Jean Luc wrote on January 31st, 2011
  12. Charlatan though Ferris may be, it’s not for providing bad information, just for hyping the revolutionary nature of information that’s mostly mundane and available through other sources. I picked up quite a bit from The Four Hour Body, so I don’t mind that I spent a few bucks on it.

    One of the arguments that I found most compelling was this thermo-manipulation. He uses Michael Phelps as an example, and I think it makes a lot of sense. Even if you believe the calories in-calories out crap, there’s no friggin’ way the guy uses- not to mention comfortably eats- 12,000 calories a day. Now factor in that he spends several hours a day in 82 degree water (which is very conductive), and has to keep his core temperature at 98.6 and you see that activity isn’t the only calorie burning factor. And we haven’t even touched the brown fat yet.

    Allbeef Patty wrote on January 31st, 2011
  13. I am thin, live in an area with cold winters, try to get outside in all seasons, and have always been sensitive to cold. One thing that’s helped is doing Crossfit — I’ve finally put on some muscle and I can tolerate the cold much better.

    Page wrote on January 31st, 2011
  14. I’ve been trying to lose weight for a week, very low carb, AND counting calories so I don’t over-do it on the heavy cream and butter… have not budged! I keep my house on 74, night and day. Soooo, I just turned it down to 71! Maybe I’ll lose some weight tonight?! So, a blast of cold water at the end of my shower tomorrow, too? Worth a shot!

    Megan wrote on January 31st, 2011
    • Try intermittent fasting. Fast 14-20 hours and day and don’t restrict calories or fat when you eat, eat until you’re sated. Lift some weights too, they will help you lose weight better than walking or light activity.
      If you are very low carb you should have lost at least some water weight already, recheck your diet for any hidden carbs.

      As for your thermostat, it’s good to turn down but it wont be enough impetus to raise your brown fat significantly. You’ll need a greater shock to do that. Gradually turn down the heat in your shower until you can just barely tolerate it and keep it there for at least 2 minutes, 5 is better, 20 is optimal.

      Yea to Life wrote on January 31st, 2011
  15. My thermostat is down to 55 at night while I’m sleeping and my window is open, no matter what the temperature is outside. Then up to 67 during the day.
    I can’t even imagine sleeping at 74. Yikes!

    Melissa wrote on January 31st, 2011
  16. I don’t know if it’s central heating, or the fact that central heating makes you want to stay indoors — in the central heating! I think you have to stay in touch with your climate, whatever it is; that’s the most important thing. Central heating and A/C remove you from what’s really happening outside, and simultaneously cause you to “dread” going out in the cold/heat.

    Kristin wrote on January 31st, 2011
  17. I’ve lived in a house heated by a wood stove and it was so cold at night I slept in a hooded sweatshirt and ice coated the inside of the windows.

    Next house was heated with central heat downstairs but no heat upstairs so it would drop into the 50’s F. up there during the winter. (A step up, right?) No AC during the summer which could get into the 90’s.

    Present house has in-floor heat (ahhhh)which we keep at 68F on the main floor and sleep at 62F. upstairs. No AC in summer, only ceiling fans.

    It usually takes me about 2 weeks to adapt to the cold or the heat. I have never noticed any difference in my weight, up or down in any of these houses.

    I do notice that we get demented in the winter and find ourselves saying things like…Wow, it’s warm today, it’s 25 F. If that happened in the summer we would all be freezing.

    I found it interesting to read how different everyone reacts to the cold or warmth. This may be a lesson to all of us to be more tolerant of others complaints of being too cold or hot.

    Sharon wrote on January 31st, 2011
  18. I think it’s about lifestyle, not just about the temperature of our houses. As in, “instead of chopping wood outside to get warmed up because it’s cold, let’s sit around inside in our furnace-heated house, watching TV, because it’s too cold to go out.” I grew up in a household where the mantra was, “If you’re cold, get moving.” I do that now, or I put on more clothes. Works for me.

    Dawn wrote on January 31st, 2011
  19. Dito Jack, John, Rob and Rita’s comments.

    Among major U.S. cities, San Francisco has the coldest daily mean, maximum, and minimum temperatures for June, July and August. (Wikipedia)

    Having said that, I will also say that I have lived there for more than half a century. It takes more than a little drive and will power to want to go outside during the Summer for a run or bicycle ride… did I mention the coastal winds? No, it may not be Arctic cold or Chicago cold but it’s still cold relative to the neighboring cities.

    After relocating to the Central Valley for work, where summer temps. range from 85-100+, I’ve found it much easier to drop weight and body fat for a couple of reasons: 1)It’s more enjoyable & easier to exercise in the warmer climate. 2)I find that my food consumption goes down during the summer months and I eat lighter fair and drink more water.

    I never slept with the central heater on, even though the house temperature would routinely drop below 60 F degrees by morning nearly year round in San Francisco.

    Guy wrote on January 31st, 2011
  20. So, that’s why I’ve lost 60 pounds since moving back to California (fall of ’09)! We had our baseboard heaters unwired to prevent our youngest setting us on fire, so we don’t have heat! ROFL! Well, that and finally eating right. :)

    Melissa Fritcher wrote on January 31st, 2011
  21. my parents live in an old large home built in 1927. the home is headed with radiators, but in the winter, my parents keep the temperature VERY low (as in 56-58 degrees) because they do not want to waste the fuel nor money on heating the entire 6000 sq ft home. they do have two space heaters they use for the living room and dining room. the kitchen heats up from the stove top and oven. this all to say that my mom has been saying for several years, since they started turning the thermostat down in the winter, that it was a factor in her weight loss, that has slowly been happening over the past several years. it made sense to me, but we had no evidence. thanks for sharing the missing link!

    sara kate wrote on January 31st, 2011
  22. I am really glad we hear our little farmhouse with wood. I get warm felling trees, splitting rounds and stacking firewood (WoW) and lounging about in the front room with two fingers of scotch and a good book on a long winter night. The winter duvet seems to do the trick at bedtime.

    Can’t budge my 65kg.

    kem wrote on January 31st, 2011
  23. 1.) It’s not a matter of one extreme or another, it’s the ability for your body to adapt to VARYING temperatures, or extremes, which burns calories.
    2.) Personally, as a teenager I slept in sub-zero temperatures (14F in the winter) and our summers (85 or higher), and with both extremes, I worked outside and worked hard regardless of the temperatures.
    3.) Muscle, whether it be the friction caused by movement, or the thermogenic properties that burn fat while sitting still, is needed (even women) to burn fat. Lift heavy things…..
    4.) Intermittent fasting increases HGH which burns fat. I use the Fast-5 method and it is working well.
    5.) Lets not focus on one certain aspect of life and think it the “catch all” to lose weight, it might help, but as the comments have shown, it’s not the same for everyone…enjoy your Primal food, your Primal play and exercise and just let the side-effects come on it’s own volition. Seems to be working for me and I stress far less (with everything in my life).

    Primal2010 wrote on January 31st, 2011
  24. One more thing, for all of you that get cold a lot, try enduring temperatures for as long as you can, and only put on a LIGHT layer, it’ll feel warmer than you realize and you still get subjected to some varying temperatures.

    Primal2010 wrote on January 31st, 2011
  25. There are plenty of fat people in Miami and we never use heating!

    Leader wrote on January 31st, 2011
  26. Hey…. just my two cents on this subject…

    I live in Finland and it’s freezing in here pretty much 5 months of the year, 4 months it’s just plain cold and the remaining 3 months we get some sun and relative warmth.

    I have to say that beyond a doubt I’m in better shape when it’s not freezing or even too cold. I don’t know if it’s this brown fat or the fact that when the elements favor outdoor activities I’m in better shape.

    Can’t say that I’ve been very active outdoors during winters cause I absolutely HATE cold – and it’s also slippery so no sprints can be done.
    So I’ve surrendered to only going to gym on the months when outdoor activities were… hindered.

    Also I want to make a point on fasting during winter… it’s tough! I get the cold hands and shivers but I’ve stuck to it and that has given me the edge on not gathering stubborn fat on the waistline… while still eating primal.
    But man, that fasting is a tough one during winter when it’s already cold. During warmer season it’s a breeze… like so many other things as well.

    BigMancini wrote on January 31st, 2011
  27. I put on a sustantial amount of weight (150lbs) while living in a house with no heating. I was freezing most of the time. I don’t think heating contributes to obesity.

    jehane wrote on February 1st, 2011
  28. You cant sit in the cold eating twinkies. However, primal living isnt only about fat loss, its about how you feel.

    I decided to lower the thermostat this morning and wear a t-shirt and I feel invigorated. Its 5C/41F in London today so its chilly.

    Cold weather, as far as I am aware, has no effect on lowering insulin levels.

    Pani wrote on February 1st, 2011
  29. I’ve never noticed a difference in where I set my thermostat in ratio to how much I weigh, but then I don’t fluctuate at all except for when I dropped 20 pounds after switching to Primal. I am happy to learn why people “get used” to winter. I was really curious but every time I had reason to research it I forgot. So I am happy to learn this new bit of information proving how cool the body is again!

    Tori Kean wrote on February 1st, 2011
    • PS. Is there a way for the average person to measure how much brown fat they have or can only specialized expensive equipement do that. It would be fun to see and experiement with…

      Tori Kean wrote on February 1st, 2011
  30. People who are in better shape are more tolerant of temperature variance than people who aren’t. This sounds to me like it could be a correlation/causation problem: I would want to see if they can correct for that (or if they have), because it seems to me just reading the article that people who are in better shape might have lower temperatures in their homes because they can tolerate it, not be a healthier weight because their temperatures are lower.

    Personal story: When I am good physical condition, I can (and do) walk around outside in January wearing only a down vest, long sleeves, a wool/alpaca blend hat, and wool-alpaca blend fingerless gloves and I am FINE so long as the temperature doesn’t fall below, say, 20 degrees (and then I am still fine for shorter walks). People ask me “aren’t you cold?!” and I can honestly say “no, I’m quite comfortable.” The cold feels refreshing.

    When I am not in good physical condition I am freezing at sixty-nine degrees and have been known to wear hoodies and long sleeves in June.

    That’s a little extreme–I have a thyroid disorder, so I’m prone to cold–but I think that makes how tolerant of it I am when I am in good condition stand out all the more.

    ahk wrote on February 1st, 2011
  31. Interesting article, thanks Mark.

    Aron wrote on February 1st, 2011
  32. I think that there needs to be more study of this and that it can go either way i grew up in a very warm place and was thin when I lived there but, when I moved to a much cooler place I gained weight. I think it has way more to do with diet and exercise than heating. Also, you have look at the big picture and find the major thing that is going wrong. I think this heating thing is minor.

    primal tree top wrote on February 1st, 2011
  33. you must’ve been short on valid topics….

    jem wrote on February 1st, 2011
  34. 17 hours into my daily fast and I’m about to do a heavy squat workout… getting sleepy (and cold!) reading this! Time to lift!

    On topic: In my experience, when I was 270 lbs (think NFL tight end body type) I was always hot as hell in the summer. Hatted the hot weather. Did fine in the cold New England winters. As I trimmed down to 215 (think rower) I’m MUCH better in the summers now… but colder in the winters. Also as I play around with carb intake and caloric intake I definitely notice a big difference between when I am fed and Fasted and hig vs low carb meals of equal calories. I tend to break my 16-19 hour daily fasts with atleast a pound of lean meat and then another 700-1500 cals. My high carb meals get me very, very warm and i find myself hot in out 60 degree apartment. A high fat intake has much less dramatic warming effect.

    Leo wrote on February 1st, 2011
  35. I had my entire family (including my in-laws) on the primal diet for the month of January. Last Friday my father-in-law comes home after having read that Yahoo article, and is parroting it like it’s the gospel truth. He proceeds to make several muffins and cookies out of the “Resistant Starches” and eats plenty of it over the weekend.

    He had already lost 11 pounds in January, without adding in exercise or going hungry. But one Yahoo article reinforcing what he -wants- to hear, and it doesn’t mean anything!

    Misty wrote on February 1st, 2011
    • Yeah, unfortunately I don’t think we can be dismissive of or underestimate the damage a silly, poorly backed article such as this can do. People will fall hook line and sinker for this “resistant carb” BS, largely because anything repeated often enough becomes truth.

      Sorry, Misty, to hear about your father-in-law’s slip. Most people like him have the best of intentions. They’ve just heard the “healthy grains” mantra too many times to ignore it.

      fritzy wrote on February 1st, 2011
  36. Come on, really? Now the advice is to take cold showers and freeze and wow, the weight will just pour off? I don’t think so.

    Shannon wrote on February 1st, 2011
  37. Interesting ideas but the whole thing reeks of correlation to me.

    While it would probably be better for our earth if people turned down the heat a little, I kind of question the premiss of this hypothesis. Gets you thinking though…

    fritzy wrote on February 1st, 2011
  38. Interesting. I have heard in the past that being cold does help you burn calories, but does it really make that much of a difference? I suppose it’s true, but I don’t think that it really is related to obesity. It may be a factor, but only a minor one if at all.

    Rob S. wrote on February 1st, 2011

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