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On the surface, their ideas might remind you of the outdated, overly-simplistic calories in, calories out model, where people are fat because they eat a few extra candies between lunch and dinner that add a few dozen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!

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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129 thoughts on “Is Central Heating Related to Obesity?”

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  1. No idea if this is related or is helping my wife and I, but we’ve started sleeping with the setting down to 65 degrees and we’re getting better rest than ever.

    The rest of this sounds good. I know that Tim Ferriss is also pushing this concept in his new book.

    1. Mark, as you can read on, people have posted some really valid points, crediting and discrediting the belief that central heating units are contributing to obesity especially in this country, yet at the same time I believe some relevant information has been overlooked. I will mention this as succinctly as possible, most of my clinical observations arise from the fact that people are not only becoming obese, which is very obvious but that obesity stems from the level of inflammation that is being overlooked, in the winter months, or any other for that matter, having cold feet and hands creates and inflammatory condition, when blood drops a couple degrees to circulate thru your body it releases inflammatory mediators, so sleeping in a cold room, and this is very subjective of course, but maintaining body heat can really improve a inflammation response and insomnia, another stressor, in this case cause by a thermal issue.
      And I agree that sleeping in a cool room improves in the quality of sleep, nothing will bomb a night of sleep faster that a hot steaming room.
      If we look at the causes of inflammation I believe we can get a much more accurate explanation on the major causes of obesity. (Blood sugar levels control, PUFAs are a major contributors of estrogen imbalances, Hypothyroidism)


      1. all my life, i have an aversion to cold.
        (cold weather, cold drinks, cold food); the warmer the better.

        it’s got a lot better since i switched my diet to hyperlipid (~ 60% SFA) so at least i don’t need gloves in summer now.
        (i kid you not; i need gloves/socks in summer).

        65F is definitely Antarctica for me. i can’t sleep in that kind of temperature (fingers and toes are too cold)

        my thyroid is normal. & all tests are normal; except i have mild Raynauld syndrome.

        exercise only warms me up when i am doing it. the moment i stop moving, i chill down in few minutes.

        did i say i hate hate hate to be cold?


        1. Hi PHK,
          I used to have the same problem staying warm. My basal body temp ran 95.8 degrees. My thyroid also tested normal, even though I had multiple clinical symptoms of hypothyroidism. Turns out that blood tests for thyroid function are horribly inaccurate. I was iodine deficient.

          Check your body temperature when you first get up. If it runs consistently low (under 97 or so) chances are good you are marginally hypothyroid or iodine deficient. Try supplementing with kelp and see if that helps you stay warm.

  2. Mark,

    I do know this…when I lived in Alaska for 4 years (Fairbanks), I gained 10 lbs that I could NOT lose…when I left the state permanently, the weight came off within 30 days. Not sure what this does for your theory…

    1. I lived in Fairbanks for 4 years as well and had that EXACT same phenomena: gained 10 lbs, left 4 years later and lost that 10 lbs in ONE MONTH!!! Interesting!

  3. I’ve been using 20 min ice baths 3 times a week for 3 weeks since reading about them in the four hour body. Not sure how much they are helping, but it’s only been 3 weeks.

  4. I have noticed. I live in Florida and always seem to be in better shape in the winter, when it is colder outside, rather than the summer when temperatures are warmer and more stable. Tim Ferris has a really good article on this in his new book “The 4 hour body” that advocates drinking ice cold water upon waking, taking cold showers, and using an icepack on your neck at night to spurn the production of hormones in your glands to produce brown fat. It’s nice to see all the sources I read about health and fitness coming together to a common point.

    1. Tim Ferris is a charlatan. You should be ashamed for listening to shim

      1. Wow, that’s the first time I’ve read that. Is that simply a sarcastic statement, or one born of truth?

        In his recent book (already mentioned), or rather the offering from his book, namely the cookbook, there are a great quantity of most excellent recipes.

        And my favorites of the bunch came from, guess where, no… wait for it… Yes! They came from Mark’s Daily Apple. And, because of them, I found my way here, and have also been pouring through the PB and the PB Cookbook.

        My conclusion is, should your words be true, rather than suspect, that you are– by extension- saying perhaps this site as well is the work of a charlatan.

        As I know this is not true, I must conclude that you were being sarcastic, especially in light of the mention of not talking to Shim. Who in the heck is Shim anyway.


  5. Seems like it’s more likely that people who live somewhere where you need to keep the heat on most of the time are less likely to be active outside and thus gain more weight. Spurious correlation.

    1. Yeah similar to how a disproportionate number of top baseball prospects come from warm climates … it’s not that a warm climate makes you a better baseball player, it’s that you can play year around.

  6. This study in Obesity Review appears to have not
    considered the Inuit, the native peoples of Siberia, and several European groups, all of whom live in cold climates and all of whom have a higher percentage of body fat. This extra fat may act as insulation. But I
    don’t think that temperature is the whole story. The peoples of Polynesia, esp. Samoa, (very warm places indeed), also tend to carry extra body fat. It implies that genetics figure in as well.

    1. The Samoans and Polynesians didn’t have much extra body fat until they began consuming refined western carbs and vegetable oils. They didn’t have nearly as much when they ate their traditional native diets.

    2. You forgot 9/10ths of Canada!
      -40 Celsius with the windchill today where I am (Saskatchewan).
      -58 in Iqaluit.

      1. I agree with you Saskie Girl. If we didn’t have central heat here our pipes would freeze, we’d be washing clothes on the stove, things would pretty much revert to 1880. People in warm places can muse about the effect of central heating all day long. We need it to live!

    1. You state the ultimate lay-scientists catch-phrase: “Association does not prove causation”, (people usually say correlation, not association), followed immediately in the next sentence by an association (and with no reference)!

      Then you post a link to your own blog post that contains dozens of black and white statements and only one obscure reference to the complexity of human physiology.

      1. Putting on more clothes doesn’t make us get fatter. Do you have any evidence to the contrary? The warmer I am, the less I eat and the more weight I lose. I always get fatter in the Winter and slimmer in the Summer, just like wild animals. This makes sense, as sub-Q fat acts as thermal insulation.

        My blog post contains 21 statements and links to a discussion and a video. If you disagree with any of what I wrote there, please leave a comment.

  7. I definitely think central heating has some impact on weight retention and weight loss, although how much is likely partially dependent on individual body compositions and metabolisms. My boyfriend has lost over 70lbs since we first met and his times of most drastic weight-loss have centred around our wonderfully frigid winters. The winter previous to this one, he lost about 20lbs between early December and late March and then only lost about 10lbs from early April until this past November. That being said, in the same period of time that he lost those 20lbs, I gained 5lbs and then dropped those plus another 2lbs over the summer, almost matching him in weight-loss (despite being far smaller and not really overweight). I can’t lose weight when it’s cold, even though we keep our house at a max of 68F and an average temperature of 65F. At night we let it go down to about 60F in the bedroom. I frequently spend my hour of walking out in the Canadian winter, which stays below freezing from December through March and still don’t usually lose more than a pound but in the summer I can easily drop 2-4lbs a month. My boyfriend is the opposite, although at a much greater scale. He can’t lose in the summer and drops in the winter (as long as we keep the house temperature low).

  8. It’s interesting but I’m not sure about the science behind it. Don’t people living nearer the equator also live in relative thermal neutrality (if anything, they get cold when they come *indoors*) yet a SAD-diet just as assuredly causes metabolic disorders.

    Additionally, overweight people, if anything, feel warmer than their thinner counterparts. Shouldn’t average temperatures be going down if obesity is going up?

    Interesting but questionable.

  9. Nothing wrong with ice baths and skiing and spending time in the cold if there’s a sauna waiting at the other end……

  10. I set the thermostat to 64 from 11 pm to 6 am and even then I sometimes turn on the ceiling fan in the bedroom.

    I did read The 4 Hour Body, and Tim’s suggestions of ice baths and cold showers but that seems like a really unpleasant experience. Art De Vany suggests switching to cold water at the end of your shower to promote the growth of brown fat and that seems to be a much easier thing to deal with. It also wakes you up better than a cup of coffee!

    The causes of obesity are complex and many but I think central heating is a minor one, if one at all.

    1. In winter, switching to cold water at the end of my shower makes me hold my breath. Not comfortable at all. We keep our house at 68 when we’re home and at 65 at night and when we’re at work.

      This is the first year in a long time I haven’t gone for daily walks outside. It’s been nasty weather, with sleet and freezing rain every couple of days, and icy walkways, so I’ve been sticking to the gym for exercise.

  11. Consider these questions: How cold does it get in the middle of winter in a tropical african savannah? And what about all the extremely fit hunter gatherer populations in the tropical forests of South America where 60F in the middle of ‘winter’ is ‘cold’?

    Also recall the premise that we are still optimally adapted for the hunter/gatherer lifestyle of early humans (and the associated environments), and so should model our activity and diet on those lines as best as we can.

    All of this makes the contention that being too warm is a contributing factor to obesity in developed countries seem rather fragile to me.

    That does not mean that there cold exposure does not confer positive health benefits (I think it does and do consciously expose myself to cold). But I think the arguments made in this post represent too much of a leap of reasoning.

    My 2¢ .


    1. Perhaps it’s a circadian thing, staying the same temperature at night as during the day. Even in the desert and tropics the temp drops significantly at night. I think that’s what is being said here. I could be wrong, though. Anyway, something to think about.
      I know I sleep much better when I turn the heat down to 60-62 degrees at night during the winter months here in northern IA.

      1. That’s exactly what I’m thinking… Longer nights in the winter + colder temperatures = longer and better quality sleep.

        The only thing I can think is that perhaps we were supposed to gain weight in the fall when berries and other higher carb food was better available… and then we’re supposed to lose weight as we use it for heat in the winter? (cyclic spring gain summer maintenance…etc.)

        Either way, I’ll take better sleep any day.

  12. I’ve actually been experimenting with cold exposure and drinking Ice Water (Yeah, 4 Hour Body- great book!) And I have noticed a marked uptick in fat loss in addition to the weight I’ve lost since going Primal this last fall.

    Feeling fantastic.

    Thanks Mark!

    -Steve Gunn

  13. I have been getting outside everyday, rain or shine (I definitely prefer shine though). I really dislike cold rainy days, partly because I am a “princess” but partly because I think even our ancestors probably didn’t like them much either. I have always turned the heat off at night, I like my room cold with a warm blanket, can’t sleep when I am too warm.

    1. I guess what I am trying to say is, while it may not be scientfically correlated, I can absolutely see a loose relation between central heating and weight gain, especially in climates where the winter weather makes it unpleasant for “princes” and “princesses” like me to get outdoors.

  14. I am quite fit and muscular and have 5-6% bodyfat. My sister is obese. When she is visiting me she always complains about the so called “low temperature” in my flat.

    I walk around in my flat in tanktops and sometimes barechested when i’m alone. I never feel any cold. She wears double sweaters and still feel cold.

    I take cold showers in the morning (well, i use almost lukewarm water to wash the soap off but i hate showering in hot water) and she says she always shower in hot water, never cold.

    I wear t-shirt or a thin sweater under my winter jacket, and it’s not even a very insulated expensive jacket either. Just a normal jacket. I don’t seem to freeze at all as long as i move around at a good pace. It’s a little boring walking anywhere with my sister because she is too slow and i have to slow down and then i might freeze a little bit.

    Here in Sweden the winters get very cold but my ancestors obviously didn’t have 800$ scientifically insulated arctic jackets or anything like that. They just got used to the temperature. Like i have.

    A prime example of primal living in the modern world i’d say!

    1. Sounds very likely that your sister has hypothyroidism. I am hypothyroid and although I lost 90 pounds, when I was obese I was always cold. I am still cold and frequently my fingers and toes turn blue but I have had this for so long that I have just learned to deal with it. I do love to sleep in my very cold bedroom though and if its too warm I dont feel well. My body temp is always 97.6 or below unless I am sick and at 98.6 I have a temp. One thing I have noticed eating primal is that although I still get cold I can tolerate the cold much better then I did before.

  15. You know, this post really made me think about how confusing it can be for people to try to get it right when it comes to their diet. I think many people agree that what we eat causes many of our health issues, however, it’s like a million “experts” that claim they have the right formula and that everyone else has it wrong. This confuses so many people. I guess in the end, you just have to decide for yourself?

    And to get more on-topic, thanks for this post. It really opened my eyes to the biological affects of the temperature in our physical surroundings. In all my years being into “health stuff,” I’ve never really thought about this.

  16. Others have pointed out that obesity is common everywhere. But not what kind of fat these folks are carrying around. Is it brown fat or white fat? Of course this is the first time I’ve heard of brown fat so I’m off to do some research. I just wanted to share a thought on others comments.

  17. Bjorn, my experience has always been that obese people tend to get hotter than those of us with low body fat. Interesting that it’s the opposite in your case. I have around the same body fat as you, however I’m always cold.

  18. I also read Ferriss’ suggestion in 4HB about cold baths. I’ve been taking 10-15 minute 75-80 degree showers/baths for about week, and I notice that my previous fat-loss plateau is moving in the right direction now. I think if you’re interested at all you should try it for some time. Worst case scenario is that you’re a little cold. I also don’t wear a coat when I’m outside (I do bring it with me though, just in case).

  19. I read another study several years ago proving that people who live in cold climates burn more fat and have less body fat in general. I moved from Boston to Atlanta and saw this theory proven in the flesh, so to speak. I myself had a harder time keeping off the fat and couldn’t believe the extreme levels of obesity here. Now granted, that has a lot to do with the traditional diet down here, but I know a lot of people who exercise religiously.

  20. Brown fat or not I cannot stand being cold, and it seems like after I dropped below 140lbs all my “keep me warm fat” disappeared. 🙁 I wish their was a solution to help my body regulate its temperature better, so I wasn’t cold all the time and bundled up like Ralphie on Christmas Story.

    1. I lost about 40 lbs, and since then my thighs ache from the cold when ever it gets around 30 degrees. The rest of my body can handle it, but for some reason it just kills my thighs.

      1. I wonder if that’s the case with me? I’ve never been overweight so I’ve only lost a few pounds, but I’ve definitely gained muscle and lost a bit of body fat (about 3% if my scale is to be believed). The past two winters have been brutal on my thighs. It’s this deep ache. The skin on my thighs is also more sensitive to the cold now. Wearing leggings or tights under my clothes has helped a lot, but it’s annoying because I have to wear them even if it’s not that cold.

  21. Hi, i kind of agree with this. I notice that in the winter i tend to put on some weight. but i think that it comes from the fact that i dont do much in the winter. i usually sit around avoid being cold beccause i dont like it. This winter im gonna try to stay active and turn down the heat during the day and see the effect.

  22. Having just returned from the freezing UK to sunny California where I stayed with my parents who heat just one room and I had to put my pajamas on over my clothes before pulling my clothes out from underneath so my poor skin didn’t get frostbite and where you have to go out in the freezing cold if I wanted to go anywhere (I didn’t hire a car) I noticed I could eat just about anything starchy (and there’s a lot of starch in England) and not gain weight. Made a change to the 10lb weight gain I usually endure.

  23. My wife is constantly cold and is a very healthy weight. I’m always hot and could stand to lose those extra pounds. Not sure if that has anything to do with it, but it is something to consider.

  24. The very first year we moved into this house we were afraid to turn the heater on until it got serviced. It was an extremely cold winter, and it was the first time in years that I lost weight without trying. I was actually eating cookies every night before bedtime in an effort to keep myself warm! Alas, the effect started to wear off by winter’s end, and I’ve never experienced this effect since, even though we never turn the heat on until November. (Which means we live through a few weeks of shivering.)

  25. I have a correlation the other way. I used to be one of those people who was NEVER cold. I have a picture from Disney Land where it looks like I’m photoshopped in, because the family is in beanie and sweatshirts and I’m in a tank top. (November in SoCal)

    However since I lost over 80lbs on PB I occasionally get cold. Maybe I burned off the brown fat too?

    I’m deliberately exposing myself to cold more and making myself endure it to get that indifference to the temperature back.

  26. I wonder how much it has to do with local adaptations to climate. If your ancestors have dwelt in an area of extreme climate for 40k years, would you have developed a way to deal with excess heat/cold along the way? Triggered genes to store fat during the lean cold months, and trickle feed from it when fresh food was not available? This may have been dealt with somewhere else before.. My mind is just wandering…

    1. I think lack of calories is the main, if not only thing telling your body to conserve fat and seek warmth. I’m Scandinavian and my ancestors probably ate plenty of mammoth steaks in both winter and summer, during the ice age there wasn’t a huge difference between winter and summer anyways.

  27. This post is serendipitous. I started reading 4 Hour Body, and the cold exposure part was the one part that made the most sense to me. I tried cold showers today and yesterday and they definitely seem to have a thermogenic effect. When I take a long hot shower I feel cold after I get out, I presume because my body reduces its heat output in response to the new external heat source. But when I get out of a 5-10 minute cool or cold shower I feel warm for an hour or more, I also have more energy. My body probably mobilizes more fat in case I’m exposed to the cold again.

    I haven’t added legumes or binge days to my diet, however. lmao

    What do the other posters think about that part of the book?

    It seems most of the examples of people for whom that diet has worked for have been obese. But almost any diet works for obese people. I only need to lose 10 lbs of fat at most, so I think I’ll stick to a low carb paleo diet.

    Tim’s criticism of fructose in fruit struck me though. I think I may reduce my fruit intake to just a few blueberries.

    1. I just finished 4 Hour Body after seeing it on Dr. Oz (who endorsed it!). I’m not willing to do the cold showers, but I am doing the ice packs at night.

      I have hypothyroid issues, so I’m always cold and have ice cold hands and feet. Since I started doing the ice pack on my neck and back at night for an hour, I’m finding I’m warmer during the day.

      I’m only in my first week of the ice packs so I don’t yet know the impact on body fat. I’ve been stuck for a while, so hopefully this will help get me on the downward slide again.

      1. You could try just an ~80 degree shower, this is more cool than cold. I’ve been starting out at ~90 and working my way down to ~50 over the course of a few minutes until I’m about to start shivering. I think the study that Tim cited about cold showers had the water at 54 degrees.

        I’m not going to do a completely cold shower though, here in Minnesota the cold water feels like ice water.

        1. I just took the temperature of my cold water, it’s actually about 60 degrees even though it feels like sub 40. Running water is deceptive!

        2. Lived in Japan for 15 years and those people soak in extremely hot baths everyday, both at home and onsens, baths so hot the water is almost scalding. Then there are the saunas … didn’t see too many fatties there …

  28. Like the rest of our bodies, which function best when they’re used regularly, our internal thermostat probably gets fat and lazy in hermetically sealed buildings. Being exposed to the elements–whether its cold and still, warm and windy, humid and rainy, or just plain hot–and then responding physiologically, takes energy.
    Being in the weather (within reason) is a barefoot experience for your whole body.
    Awaiting Marks’ next post on primal nudist colonies…..

    1. I agree with this. Let your body regulate your temperature.

      I adjust my thermostat as close to ambiant outdoor temps as I can be comfortable in when dressed appropriately for the climate and season. And that’s a bit over 80 (with fan on) in summer and upper 60s in winter. I’m disappointed in myself that I can’t go lower in winter. But then again, it’s actually colder than that thermostat setting near the floor and in the rooms I am in…

      And I go outdoors a great deal.

  29. … when i saw this headline the other day somewhere else – i couldn’t help but think “jeeeze – they’re really grabbing for straws now – or headlines…”

  30. Since going primal,I’ve tried to turn down the temperature on my showers, at least to warm (I used to take them scalding hot). Of course, I can’t say how much of my overall improvement has been related to the cold water, since I went primal at the same time, but I do seem to have more energy after I shower, especially if I use really cold water at the end.
    I’ve read research before about more chlorine being absorbed by the body with hot water, so that was my reason to avoid it.
    We also just made the change to cooler temperatures at night (and during the day too) and everyone , including the babies, seem to be sleeping better.

    1. That’s true about the chlorine. Warm and hot water opens up your pores and allows the bad chemicals in water into your body, and there are more bad chemicals in tap water than just chlorine.

  31. Hmm. I dunno about all this. In my experience, I’ve carried around 50+ extra pounds for the last 20 years and I am always freezing despite the insulation. For three years we’ve lived in coastal NSW and our old house is COLD in the winter. We’re talking average temps of 52F during the day, colder at night and that’s just indoors. I couldn’t drop weight without trying.
    Interestingly enough, my body temp is regulating better now that I’ve lost 20 pounds since August. I’m sweating more, too. And I have to say the weight is coming off much quicker now that I’m following primal principles and not good ol’ CW.

  32. So why aren’t there more fat people in equatorial countries? There are some; it’s a myth that no fat people exist in developing countries. (So much for the calories in/calories out model.) But you’d think there’d be a ton of them if lack of “thermic stress” or whatever you call it, was a contributor to obesity.

    1. Probably has more to do with lack of food. Mexico has huge rates of childhood obesity since adopting a more Americanized diet. IIRC Mississippi is the fattest state in the union. If you google ‘fattest states’ you can see they tend to be southern states. Why is this?

      1. I think the main reason that these southern states are the fattest states has more to do with poverty rates than temperature. Obesity rates in the poor are disproportionately high when compared to the rest of the population.

  33. I think that a cold bath/shower/plunge that many are mentioning is way, way different than living in a house with less heating. The positive effects of cold plunges have to do with the shock to your system, blood flow and endorphins, etc.

    Living in a cold house can cause weight loss- the one year we had the indoor temp at 45 we were shivering so much that we lost weight. We also looked like hell and were grumpy.

    Now we heat to 55 or 60 during the day, down to 50 or 52 at night. In the summer the inside temp is the same as the outside so usually 75-80. This type of heating and cooling saves money, but I don’t think it does a thing to our weights.

  34. Whatever the answer is to this question, it makes me feel better before my 20 minute walk home in -4 degrees Farenheit. Brr…. when do my winter vibes arrive?

      1. I haven’t seen them anywhere but on Mark’s weekend links post. My eyes are peeled though!

  35. Mr Grok thinks you are either a polar bear or a brown bear, he’s a brown bear, he is rarely warm, wears lots of layers when outside in our Scottish winters and defines ‘jumper weather’ (ie more than a teeshirt) as 16 degrees and below! However anything over 25 and he’s not that happy either!

    Me, I’m a polar bear, tonight I was at yoga in a vest and shorts, everyone else was wearing layers and complaining it was cold (they are all overweight bar one). I have to sleep in a cold room with a window open regardless of outside temperature. We have the heating switched off from 10 pm unless it is going well below zero in which case the radiators are set to frost setting!

    But I also love the heat; even raced an IM in the mid 30s without difficulty. I find weight loss harder through the winter regardless of exercise protocols – I’m sure that’s a day length thing and hiberation! Squirrels will store fat in the autumn irrespective of food supply they have, if need be they convert their muscle to fat ready to overwinter so that is being triggered by either temperature/day length or both I guess.

  36. Right. anything to keep from facing the fact that we have been led astray by the CW and that it’s the carbs (specifically the refined garbage) that has caused us to become a nation of obese, unhappy folk.

    Exercise has nothing to do with weight btw. It only increases your appetite. It’s great for getting fit but don’t count on it to lose weight. But TPTB don’t want to discuss THAT either.

    Better to blame it on central heating. Yeah. That’s it. Think of the money we’ll all save as we sit around in our 50 degree homes in the winter shivering off all that fat.

    And just for the record, I’ve kept our home at 68 daytime/63 nighttime for decades now. Hasn’t helped either of us in the fat department.

  37. I’m lucky. I live in San Diego, just moved into my new place 2 weeks ago and have yet to need any heat here in January!

    1. Its crazy how I stumbled across your comment…

      Where did you live before? Outside of SD or somewhere else? I live in Grand Rapids, MI and hope to move to Cali before 2012 strikes.

      Great blog by the way! I came across your honey nut cheerios post which is crazy since I stocked honey nut cheerios today and thought about how I could easily make a blog post out of that since millions believe it is healthy for absurd reasons.

      I will still write my own version of it but will definitely link to your post this weekend or the next!

    2. It’ll be interesting to see if that cold tolerance sticks. My own experience living both in California and the Midwest is that your body adapts to the local climate pretty soon; this is why visiting tourists from cold places are wandering around in t-shirts while the locals are bundled up in jeans and coats, complaining about the cold.

  38. 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.

    1. 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.

  39. 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. 😀

  40. 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.

  41. 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!


    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!

  43. 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.

  44. 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!

  45. 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?

  46. 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.

  47. 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.

  48. 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.

  49. 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!

    1. 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.

  50. 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!

  51. 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.

  52. 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.

  53. 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.

  54. 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.

  55. 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. 🙂

  56. 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!

  57. 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.

  58. 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).

  59. 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.

  60. 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.

  61. 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.

  62. 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.

  63. 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!

    1. 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…

  64. 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.

  65. 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.

  66. 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.

  67. 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!

    1. 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.

  68. 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.

  69. 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…

  70. 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.

  71. How does this relate to obesity in people in tropical climates. When in Thailand I would give anything to be cool at night at times but obesity has exploded there in the ten years since I first started visiting there. I have seen an increase in obesity both in cities and up country where I visit my wife’s family.

  72. Thermogenic fat loss has been covered before here: This is a good re-visit of the issue. My fat loss had plateaued after losing 20 pounds in the first two years of going primal. I couldn’t lose the last stubborn pounds.

    This December I exeperienced an ephiphany. While learning how to ski in Switzerland, I spent hours in frigid conditions. The activity of skiing itself wasn’t strenuous. But the time spent outside in the cold enabled me to lose 7 more pounds very easily.

    I also read the chapter in Tim Ferris’s book The 4-Hour Body, and decided to use a form of cold-water therapy to replicate fat loss, or at least keep the fat from coming back in January. After a workout, I would sit 10 minutes in a steam sauna, then 10 minutes in a 66-degree plunge pool. It’s working.

    I wouldn’t use this to lose fat initially, or to go from obese to slim. I think the primal diet works much better for large amounts of fat loss, followed by exercise. Thermogenics is just another weapon in the arsenal. It may not work for everyone. The side benefits include reducing post-workout inflammation and muscle soreness, and some claim that it helps build immunity.

  73. Hi, Dawn,

    thanks for the info.

    my resting body temp. was lower than most people, not as low as yours tho. but that was before my hyperlipid diet.
    i should check again.

    the only thing is i don’t have a weight problem.

    i even got frost bites once on all toes & fingers once.
    since all tests were normal, the only advices i was given were “keep warm”.

    i tried OMDs/acupunturists.
    they told me i’m of Ying composition so i should “avoid cooling food or drinks” (like salad, ice cream, fruits, cold drinks, etc) & eat “warm & nourishing food w/ meat…”

    another thing to avoid is “wind”


  74. Definitely a connection – I see it in myself and also in my dogs. I feed my dogs more in winter but they stay the same size and weight. That’s because they burn more calories simply staying warm.

    And you could have a whole other post on weight and remote controls! Same principle – we live in a society dedicated to making life easier and more comfortable and all the time we get fatter and fatter.

  75. Interesting,Being from the NorthEast with Huge temp swings,I have found cold weather makes me put on a layer of fat. Disclaimer:Before everybody gets worked up I am a runner, 2:32:00 marathon 31:40 10 K, 5’9″ 160 pounds usually 8-10% Body fat. I was also a full time ski instructor at Killington for years. As a ski bum I ate very little,was sking 6 hours a day,then doing my 8-10 mile runs at night, Every winter I would put on a layer of fat that would disappear every spring as soon as it got warm, food intake did not vary much. I always attributed it to the body putting on a layer of insulation for the extreme cold(Vermont). I also remember a study that was done on elite swimmers in a pool where one study was done on training in a warm pool 70 deg.And the same swimmers in much cooler pool 50 deg. The period when swimming in the cooler pool reveiled higher fat levels retained over the same workouts and food intake.
    At a certain temp does the body actually go into a A”fat saving mode” to cope with cold weather? Onthe other side I am also aware of Polar expeditions where 5-6,000 calories a day are required to keep up with demand.
    Any Info on this?
    Many thanks!

  76. While cold might stimulate the metabolism, it also certainly makes people hungrierrrrr. I’m not sure shivering away a few extra calories can make up for the non-Primal muffin that suddenly looks magically appetizing the moment the temp drops below a certain threshold….

  77. Hello!

    This makes very interesting reading!

    I find that I put on weight during the winter months, and that I lose a lot of weight in the spring months (so March April and May). This stays the same level until around October.

    I have always thought this as due to my unwillingness to go outside and exercise and my willingness to cosy up under a duvet and hybernate. And then Spring arrives and I can’t get enough of the longer daylight hours.

    I suppose the lure of the artiical warmth can stop us from being active.

  78. I work in a factory. We make all sort of bedding.
    No retail. Just manufacture.
    Business has been in existance since 1959.
    I set the meter on 6, which correlates to about 70 degrees F. on a duvet and used vicuña and it is a better sleep. You guys are right about the temperature.

  79. I have wondered about this for a long time, though I think it goes further than just modern heating systems, and also relates to modern cooling.

    The heating connection is obvious, and anyone who spends time outside year round will tell you that being out in the “cold” really wipes you out. Even before you get to the point of shivering, your body is using up more energy to keep itself warm. Scouts know this, which is why they try to serve good “hearty” meals on cold weather trips — some primal, and some not. Direct warming (from having something warm in your stomach) is only part of it.

    But what does modern air conditioning (primarily cooling) do for/to us? I know in my case it boosts appetite. All other things being equal, when I am hot, I am not as hungry. I remember plenty of times growing up (in a non-AC house) where by dinner time we were almost too hot to eat anything. Meals were “lighter”, and even so we didn’t eat very much.

    By keeping cool all the time, are we tricking our bodies into thinking that we are stuck in a perpetual “fall”? Is this triggering some kind of body response that suggests it is time to put on fat for the winter? It would be an interesting research area if someone could figure out how to measure it.

    I would argue that the American obesity trends correlate better with modern cooling than with modern heating. I am not discounting the contribution of diet, only suggesting that it is more complex than *just* what we eat.

    This is all the more reason to get outside, often, and to do it year round.

    BTW, I don’t see an area for “welcome” messages, so I will just add here that this is my first MDA post. I have been reading here for months, but I just made the plunge. I have been eating more primal for less than a week, but I am already feeling better and I have lost some initial pounds. “Water weight”? Probably, but it is an encouraging start.

  80. I moved from TX to Michigan and this is my first winter ever to experience snow. Everyone says I am lucky bcs this is the warmest winter ever but it’s too cold for me. I have lost 10 lbs so I am now 109lbs. I hate the cold and was getting worried about my weight loss since I have been eating whatever I want. I met a friend here who moved from South America a few years ago during one of the worst winters in years and lost 30lbs. She said it only happened the 1st winter though and has gained it back. She was too happy to be worried about it but I have been worried. I go to school so I have no choice and just try to walk as fast as possible when outdoors.

  81. i think it has to do with places being to cold, hot and vitamin d levels, and sunshine as i think summer and winter survival mechanism to decrease energy for self preservation during wintery conditions .
    the far south areas are really hot which causes ppl to stay inside most of the time with cool air, countries to the far north are really cold thus ppl stay inside for heat and are not exposed to much sun.
    places like america ppl make plenty of money to buy tech and entertain themsselves inside. ppl buy homes and stay inside to stay cool and warm and theres winter 1/2 the year . and lastly the middle east isnt exactly well developed with income and tech most ppl are usually strolling around as theres not much to do and theres plenty of sunshine.
    anyone else have a theory.

  82. Interesting article. I might mention I grew up in Melbourne Australia for the first 42 years of my life. The aborigines say it has 6 seasons in that area of the world. We use to say all 4 seasons in one day. I LOVE THE COLD the more freezing the better. When winter temperatures were below freezing during the 60’s and 70’s, I would ride to school on my push bike in short pants and no jumper and short sleeved shirt and wonder why every one was saying it was cold. I use to sweat at that temperature or at least be very hot. I always drank hot drinks and ate heavy foods – Pies, chips, roasts; etc. Not many salads. I moved to Queensland at 42 and took about 7 years to climatize. Still not sure if I really have adjusted even after 12 years. Recently, I went to Melbourne to visit my daughter and got a bad bronchial flu after about 4 days of extreme cold weather. I did though enjoy the cold wind and rain and the freezing on my skin. I still did not wear any coat and went about in thongs, short pants and a short sleeved shirt for the time I was there just as I do every day in Queensland. Despite getting ill I still did not feel cold. I have found since being in Queensland I do little physical activity as its way too hot for me, hence I have piled on the weight because I am so hot and sweaty all the time. I have no energy and also no incentive to do anything of interest that is physical because I rent and have to move house so frequently. Additional I have now been diagnosed with sleep aponea which is a cause for – high blood pressure and AF ( heart flutter ) which all contributes to sweating and low resistance to heat as well as overweight. I have all these issues as well as a constant low energy level and need to sleep a lot. Additional to this I get gout which can be triggered by stress, related to dehydration and heat exposure. I don’t take drugs, I don’t smoke and I don’t drink alcohol and never have.
    I never had these issues diagnosed in Melbourne when I was younger, but have had them only show up in hotter weather as I have gotten older.

  83. cold adaptation (think ice baths) and heat adaptation (think sauna) have both shown undeniable benefits to improve health in relatively healthy individuals. olympic and professional atheletes have been using these methods for decades to modify epigenetics for better performance and recovery.