Ketosis, IF, brown fat, and being warmer in cool weather


I’ve always enjoyed cooler weather. I’m usually the last guy wearing shorts in Fall and the first to wear them in Spring. I usually switch to pants around the freezing mark.

But now that I’ve been intermittent fasting along with keto most days for over a month, I’ve noticed a change: I’m able to stay warm in colder temperatures than before. This morning I was out for a twenty minute walk in -8°C (17°F) in 25 km/h (15 mph) wind, still in shorts and a t-shirt! I certainly felt the cold, but I never shivered, and after ten minutes I warmed up.

It turns out ketosis enhances the ability of brown fat to create heat:

I also noticed my breathing increased, presumably to deliver more oxygen to my brown fat.

Has anyone else experienced an increased cold tolerance after keto and intermittent fasting?

Dr. Benjamin Bikman - ‘Insulin vs. Ketones - The Battle for Brown Fat’
(Erin Macfarland ) #2

COOL! Really interesting study thank you for sharing this!


I have gone the other direction. I am much colder these days, than previously. I wish I could stay warmer, since I live in a area that has a long cold winter. But without my extra padding, I really have to rug up for my walks these days already and it is only autumn.


If you have a long winter, it may be a bit late this year, but one thing that helps a lot of people build up a tolerance to cold is to consistently experience cool temperatures at least a couple hours a day. Be cool enough to get goosebumps, but go warm up if you start shivering. It can be as simple as not wearing a jacket when walking outside. I’ve seen this technique help many people. It’s basically what they did with the mice in the study.

Do you think your metabolism slowed down? If I start feeling like I can’t stay warm, a feast usually cures it.

(Keri) #5

I’ve notice the same. Though it’s not that cold here (Florida), I have enjoyed swimming in a cold pool more than ever.

I found this a few weeks ago and was compelled to dive down the brown fat rabbit hole:

Cool stuff.


Nope, I seriously think it is my fat layer isn’t keeping me as warm. I wear light jackets with a ski cap if the wind is blowing, I know how important it is to aclimatize myself for winter now. . I do a couple of outside walks almost daily, DH has T2D so walking drives his numbers downward, so we walk often. I have plenty of energy, can eat just about anything my heart desires. ( I don’t want starchy and sugary carbs at all anymore). Since I have been keto/lchf for over a year now, I am not blaming it on metabolism. My TSH is healthy too. I just feel the cold more than I used to, not a big concern, I have plenty of rug up stuff to wear. I’d rather be slim and cold than fater and warmer :slight_smile:


I am much colder as well. I cannot even read the thread about cold showers, the idea makes me shiver too much.

Have been IF since March, Keto since April. During a fast I get cold, especially at night.

I used to be the person that never put away their short sleeve shirts. I had no need for sweaters. Now even in May I was freezing. The only new clothing I have bought is outwear

(Todd Allen) #8

I used to have miserable cold tolerance and now it’s quite good. But in addition to eating keto I’ve been intentionally engaging in thermal stress, both cold and hot.

And my cold tolerance still varies widely. Poor sleep, sickness and sometimes extended fasting can cause my tolerance for cold to plummet until I correct the problem.


It’s finally below freezing here in the midwest. I remember reading an article about brown fat and white fat and being cold. Supposedly you can eat more food in the colder weather because your body is working harder to stay warm. Although I’ve also heard from runners that exercising in hot weather also burns more calories. I wonder how this fits in with the keto diet where fat is used for energy. Some people do cold showers and polar bear plunges to try to shock themselves.
I found this guy Wim Hof that is pretty extreme setting world records to do with being cold:

(Omar) #10

In the past you had damaged metochonderial DNA mainly due to free radicals which can be caused by overeating or pollutants.

Keto/IF combination regenerated the damaged code. and hence the non utilized energy is converted into heat by the metochonderia

Let me see if I can remember the referance

(Bunny) #11

Maybe it depend on how much fat you have at the time and how much time and effort is placed into overcoming fragility in attenuating your immune response to colder conditions to excellerate the conditions by which white adipose tissue (WAT) and brown fat or BAT can become more iron rich in mitochondria…

Advanced forms of meditation (cardiorespiratory synchronization/cellular respiration) helps in the process and creates even more telomerase (longer telomeres) which leads to longer extensions in longevity on top of the benefits of cold thermal adaption!

You want to kill cancer, you do the opposite through exposure to thermal heating ratios!

(The amazing autoimmune 🦄) #12

That is interesting. I had never heard that about meditation. I would like to read the article. Source?

(Bunny) #13


Keep in mind most of this telomere and it’s connections to meditation in the research is most likely based on a sugar burners metabolism?

Imagine what would happen when you cut down the processed carbs and sugars?

Also keep in mind sugar burners are increasing and maintaining the length of their telomeres simply by practicing meditation?

For example if you examine a persons DNA or the length of the tips of the chromosomes (telomeres) that has been practicing Transcendental Meditation ™ under high powered microscopes they (scientists) cannot tell how old they are (e.g. looks like a 12 year old but the person is 40 or 50) and they are sugar burners and some don’t eat meat (viz. vegans who’s primary source of nutrition is carbohydrates)?

The shorter the telomeres; the less time you have to live!

  1. Cortisol, Stress (AF), Meditation & Cardiorespiratory Synchronization = Restful Alertness
  1. More breathing – longer telomeres
  1. Can meditation slow rate of cellular aging? Cognitive stress, mindfulness, and telomeres: Given the pattern of associations revealed so far, we propose that some forms of meditation may have salutary effects on telomere length by reducing cognitive stress and stress arousal and increasing positive states of mind and hormonal factors that may promote telomere maintenance. Aspects of this model are currently being tested in ongoing trials of mindfulness meditation.
  1. Zen meditation, Length of Telomeres, and the Role of Experiential Avoidance and Compassion: Although limited by a small sample size, these results suggest that the absence of experiential avoidance of negative emotions and thoughts is integral to the connection between meditation and telomeres.
  1. Insight meditation and telomere biology: The effects of intensive retreat and the moderating role of personality: These findings suggest that meditation training in a retreat setting may have positive effects on telomere regulation, which are moderated by individual differences in personality and meditation experience.
  1. Elizabeth Blackburn on the telomere effect: ‘It’s about keeping healthier for longer’ BTW She discovered telomeres!
  1. Real Age Test

(The amazing autoimmune 🦄) #14

Thanks so much🤓Fascinating stuff. I did know about telomeres but had never heard of meditation affecting their length. I think I see meditation in my future.

("Don't call it calories, call it food") #15

Greatly enjoyed this interview, thanks.

(Bunny) #16

Wim Hof

Meet "the Iceman"

Today’s video features Wim Hof, world record holder for the longest documented ice bath (an hour and fifty-three minutes and 12 seconds). He was recently a guest on the Tim Ferriss show and the Joe Rogan Experience.

The video begins with a little discussion of Wim’s world records, including things like the longest documented ice bath and many more. In 2009, he climbed the top of Mount Kilimanjaro in his shorts within just two days. He also completed a marathon both in Finland (−20 °C, barechested in shorts) and, in 2011, in the Namib Desert… without water.

In this podcast, Wim gives some of his back story including some of his early spiritual and physical pursuits, like the practice of Yoga, and how this eventually culminated in him, almost on a lark, beginning experimenting with the practice cold water immersion. After this initial experience where Wim discovered that it made him feel “great”, he went on to continue to develop his technique for withstanding even more cold (intuitively being “taught by nature”, as he describes it), and now has learned how to teach the technique effectively to others through workshops and online videos. The Wim Hof method involves a combination of cold exposure, breathing techniques, and meditation.

The Science Behind Wim Hof’s Breathing
While Wim isn’t a scientist, he’s allowed his method, particularly the breathing techniques, to undergo some scientific scrutiny. After a pilot study in 2011featuring only Wim, a larger was completed and published in 2014. This study included 12 individuals that trained with Wim, even doing their own mountain ascent, and then 12 controls that did not undergo any training. Both groups were then injected with bacterial endotoxin, which elicits a potent immune response in humans and other animals. This is a pretty standard measure of immune response. Afterward, the the response of the participants immune systems and endocrine systems were measured. There’s a few pretty amazing things that stand out about this study…

  • The 12 individuals that trained with Wim were able to increase their epinephrine to levels above what are normally seen in bungee jumpers while practicing just Wim’s breathing techniques by themselves. This is likely due to the fact that epinephrine (also known as adrenaline) increases as a consequence of both hyperventilation and transient, mild hypoxia due to breath retention. This has been shown in several other publications.
  • Wim’s trainees produced about half as many pro-inflammatory molecules (like TNF-alpha), and around twice as many anti-inflammatory molecules (like IL-10). Not only that, but the anti-inflammatory IL-10 peaked almost an hour earlier than in the control group, which prevented the immune response from spiraling out of control and causing more tissue damage. In other words, in general, they tolerated the inflammatory assault to their immune system much, much better than the control group. The anti-inflammatory effects that were measured in Wim’s trainees were likely due to the increased epinephrine. Previous studies have found that exposure to epinephrine suppresses the pro-inflammatory cytokine TNF-alpha and increases anti-inflammatory cytokine IL-10 in humans injected with bacterial endotoxin.
  • Finally, if these immune system feats weren’t interesting enough, the study found something else out that stands out: Wim’s breathing technique induced a change in blood pH in his volunteers from the more physiological ranges of 7.3 to 7.4 all the way up to an average of around 7.75, a range that qualifies as mild respiratory-induced blood alkalosis. This has been shown to occur due to a decrease in blood carbon dioxide levels.

Wim Hof Method, Pain and Inflammation


Figure 1 Before meeting Wim Hof, I talked to an acquaintance of his, Dr. Pierre Capel, at a conference (very serendipitously), and he’s actually the person that exposed me to the idea that part of Wim’s super powers (when it comes to withstanding cold) may actually be from his breathing techniques. When Wim practices his breathing techniques it actually raises blood pH to a very high level (7.75 average pH in the 2014 study). This is accomplished from a precipitous drop in CO2 in the blood stream. This level of pH, which is more basic than usual and represents a mild form of respiratory alkalosis, is actually high enough that it very well could mean that the pH itself is actually de-activating nociception (pain-induction) ordinarily triggered by what are known as acid-sensing ion channels (ASICs for short) when your body is exposed to cold or inflammation in general. In other words, acid-sensing ion channels (which activate nociceptive receptors and cause pain) are active at a lower pH and inactive at a higher pH (Figure 1).

This is an excellent explanation of what’s going on with Wim, and something that I wouldn’t have known about if Dr. Pierre Capel hadn’t told me. Pierre is also a really interesting guy with a background in science, which is exactly why I filmed a podcast with him as well! (See the bottom of this email.)

Finally, one thing to note about some of the dialogue surrounding inflammation:

While Wim conveys a sense of confidence that the evidence will continue to bear out profound benefits from his technique, the first author on the most recent study from 2014 did warn that this study’s results do only look at the short-term response to an inflammatory insult, and not conditions of the more chronic variety yet. I don’t blame Wim for his optimism, but I think this caveat is fair.

Nevertheless, I remain optimistic and look forward to the continued research taking place exploring questions of whether or not his techniques can help with chronic inflammatory disease, and especially, depression, which I understand to be taking place.

Cold Exposure and Norepinephrine
One of the consistent themes of the things that Wim tries to convey about his technique and the practice of cold immersion in this podcast is that it makes him feel good, and he believes this is through the activation of the parasympathetic nervous system. In a sense, Wim makes the argument that by immersing himself in this stress temporarily, he is actually sort of fast tracking his own brain to a state of mind that is similar to that achieved through more conventional meditation practices.

One of the things I bring up during our conversation, and what made me somewhat interested in cold shock before even having met him, is that cold stress has been shown to increase norepinephrine in the blood by up to 2-3 fold, and also been shown to be released from the locus coeruleus in the brain after cold stress. This is especially interesting since low norepinephrine is associated with depression and increases in norepinephrine (via norepinephrine reuptake inhibitors) have been shown to ameliorate symptoms of depression. This actually gives a pretty great explanation for any sort of narrative about subjective mood improvements being had from the sort of extreme undertakings Wim’s made a name for himself with.

Dr. Pierre Capel on the Power of the Mind & the Science of Wim Hof

Dr. Pierre Capel is the gentleman I mentioned bumping into in Amsterdam who explained some of his pretty convincing theory (summarized above) of just what’s going on biologically with Wim’s method that makes him so successful at attenuating the acute inflammatory process; withstanding cold.

It’s a great conversation, and Pierre himself also has a scientific background. In addition to the cold/pain receptor stuff, Pierre also has a diverse array of interests, including some of the science behind the practice of meditation, and we talk about that here too.

I don't want to track but am gaining weight