Is A Low Body Temperature Bad?

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If you’re wondering whether or not a low body temperature is a bad thing, well, here’s some interesting results!

A study was published just the other day on mice that were engineered to have a lower body temperature than normal, but they could eat all they wanted during their lives. I’ve wondered whether or not a low body temperature is part of the reason why calorie restriction extends lifespan, and this research may show us an answer to that question.

Calorie restriction works on many different levels to extend lifespan in different species. This particular study which was conducted found that men who have a lower body temperature than average are actually living longer than their peers who have a normal body temperature. It is also worth noting that they were not on a calorie restricted diet either.

Calorie Restriction Diet Lowers Body Temperature

Have you ever noticed when you eat less, or you simply fast, your core body temperature seems to decrease?

Well, what if you were cold all of the time? I don’t mean cold in that you’re always shivering, but just a little cooler than normal, like a degree or so.

The magic of calorie restriction seems to partly be because it lowers body temperature. It’s certainly not the only thing, but we know from previous studies that a reduction in body temperature is required in animals for them to have protection against cancer, while on the diet.

When researchers raised the ambient temperature in studies involving CR’d mice, increased the animal’s body temperature, and they lost their protection against common cancers.

Calorie restrictions lower body temperature quite quickly, but after a while, you tend to get used to it, or the effect on body temperature isn’t as dramatic once you stabilize from the weight loss.

What if you already have a low body temperature?

Well, in this case, you could be lucky! But first of all, you want to rule out any causes that may not be so healthy. A good idea would be to get a full blood panel done to check your white blood count. Check if you have a thyroid problem or if you have any symptoms which may indicate poor circulation? Calorie restriction can cause you to have cold hands and feet, so it’s not by itself a sign of poor circulation.

Calorie restriction lowers metabolism and decreases thyroid hormones fT3, and fT4, but TSH should be within normal limits. If you have this then you are fine, but if there is a problem, a thyroid panel will pick it up.

My father already has a low body temperature and says he always had a low body temperature. Interestingly, he actually looks a lot younger than his age as well, but this may have to do with the fact that he ate really healthily when he was younger.

What is my body temperature on calorie restriction?

After seeing this study I thought that I should see how low my temperature does actually get in the mornings, especially when I increase my overnight fasting time. I woke up around 8:30 this morning and took my temperature right away, and it showed 34.85 Degrees Celsius! That is really low! I feel fine though, so not a problem for me… But I didn’t expect it to go that low.

I just bought a ‘Braun Ear Thermometer’ to take more accurate measurements, and it’s really quick and easy to use. You don’t have to wait forever until you get a proper reading because it takes the temperature from the tympanic membrane, where one of the main blood vessels runs through.

Having a low internal body temperature is a good sign that you could be effectively slowing down aging and protecting yourself from cancer. Having a low body temperature may also have unwanted symptoms, so if you have any symptoms associated with hypothermia, increase your calories a little.

Potential dangers

Although having a low body temperature might be beneficial to slow the aging process, you have to be careful that you don’t expose yourself to very cold temperatures where you could be at risk.

If you don’t have enough fat on your body and you’re not able to generate enough heat, making sure you wrap up in colder weather is important. Take supplies with you and extra blankets or coats in the car if you’re out.

These are just some of the sensible and simple things one could do to protect themselves from literally freezing to death if they happen to get stuck somewhere.


[1] Scientists unravel the secrets of long life

Updated and reviewed: January 2019

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  • I, too, look about 15 years younger than I actually am, so I thought I’ll check my temperature too (I have a different model Braun 6013 than the 4520 you have). I just took my temp a few times in a row and am getting ranges between 95.0 and 96.7.. and I’ve been already up for a couple hours. So, that’s pretty low.

    Very interesting!

  • No, not at present, though I am working on changing my diet, and am giving a thought to attempting CR again.

    Also, up to my late 20s, I was considerably underweight for my height (5’7″ at about 125 lbs), and so it’s possible that I may have practiced CR on some level without intending to.. but if so, it was completely unconscious.

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