Is eating less making me cold?

March 19, 2006 7:54 AM

Does not eating, or eating very little, affect body temperature?

Some pretty devastating events in my life over the past month have had some equally devastating effects on my appetite. For three weeks or so I would eat roughly one meal a day or less. <1000 calorie days were very common. Over the past week I've started feeling a little hungrier and thus eating more, but I can tell this has had some significant effects on my body. (I think my stomach has shrunk, for one, because I can only eat half the meal size I used to eat regularly, even if I feel as hungry as I used to.)

I'm cold all the time now, even when I'm wearing layers. Historically I would sleep very comfortably in just a pair of boxers or pajama pants--anything more would almost always lead to me waking up with the shirt I was wearing soaked with sweat. Nowadays, I've been wearing sweatpants, t-shirts and socks to bed, and I'm STILL cold. It takes me a long time to warm up under the comforter. Do the effects on my metabolism from eating so little affect my body's production of heat?

For what it's worth, I'm 5'8.5", male, and around 180 pounds (and I've lost a few pounds since this started.)

posted by Kosh to Health & Fitness (18 answers total)

How much is "a few pounds"? I once rapidly lost 40 pounds, and for months after losing most of that weight I was really cold all the time. I always assumed I was cold because my body had not yet adjusted to having less insulation.
posted by amro at 8:22 AM on March 19, 2006

"A few" in this case is 4~5.
posted by Kosh at 8:25 AM on March 19, 2006

In high school biology they taught us that eating was a way to maintain homeostasis. Implied in that, I think, is body temperature regulation.
posted by danb at 8:35 AM on March 19, 2006

If you're eating less than your body requires for homeostatis, then it will require using long-term calorie storage (i.e. fat cells or muscle tissue) to make up the difference. Converting fat or protein into fuel is a slow process, so you body may not have the surplus to do more than maintain core temperature.

In short: I believe so, yes.
posted by Mozai at 8:45 AM on March 19, 2006

Yes, absolutely. In fact, some anorexics' bodies grow a layer of fine hair everywhere as a last-ditch attempt to stay warm. (I don't mean to suggest that you're anorexic -- that's obviously an extreme example.)
posted by booksandlibretti at 9:29 AM on March 19, 2006

It often happens that someone on a fairly severy calorie restriction diet sees a drop in their body temperature -- this is the body's means of lowering its own energy usage in preparation for drought of prolonged hunger.

Also, psychological depression is also often accompanied by a drop in body temperature. So it's possible that either factor, or both, is at play.
posted by curtm at 9:58 AM on March 19, 2006

As always, I'd recommend a trip to the doctor.

I don't know, but I would guess that your actual body temperature is still in the normal range, and that you're not actually hypothermic, given your weight. Lack of caloric intake can definitely cause hypothermia, but this is generally seen in severe malnutrition, as far as I know, not a month's worth of poor nutrition and weighing 180 lbs.

Two thoughts: you could be experiencing "cold intolerance," or actual hypothermia, due to thyroid hormone dysfunction. Your doctor can easily test for that. I don't know much about your devastating events, but if you're feeling stressed out, anxious, or on edge, you could be putting out higher doses of epinephrine, which will cause constriction of the blood vessels in your skin, and make you feel cold. Happens to me when I'm feeling very stressed.
posted by gramcracker at 10:09 AM on March 19, 2006

I'd second a trip to the doctor, could be hypothyroidism as gramcracker stated.
posted by 6:1 at 10:40 AM on March 19, 2006

Some pretty devastating events in my life over the past month

I wonder if your feeling cold has to do more with shock than food (or lack thereof).
posted by deborah at 12:11 PM on March 19, 2006

Failure modes from not eating I have seen include: getting sleepy, getting cranky, getting indecisive, passing out, getting terrible hunger pains, getting cold. For me, it's always been getting cold. Your experience sounds very familiar.
posted by Aknaton at 1:09 PM on March 19, 2006

Thank you all for your answers. :) If this continues for another week or two I'll be going to the doctor for sure. I will keep the thyroid things in mind. As it stands, though, I expect my appetite to steadily return (as it has been doing) as I deal with the situation. I'm not terribly alarmed... more annoyed than anything, because I'll wake up and then be unable to get back to sleep because I'm freezing.

The weirdest thing about it has been the suppression of hunger. I just didn't feel hungry at all, and for the first two-two and a half weeks the thought of food made me want to vomit (that in turn made it very hard to force anything down, because I was sure it would come right back up.) I've gotten better since then, and I've seen a steady improvement trend. I'm trying to eat little things during the day to get my caloric intake back up to a healthy level.
posted by Kosh at 3:16 PM on March 19, 2006

Eating a low calorie diet implies not eating much, which can definately cause a nutritional deficiency of some sort, which can be responsible for all kinds of problems.
posted by blue_beetle at 5:16 PM on March 19, 2006

This is familiar to me, too. (Got dumped, suddenly depressed, couldn't eat, sat semi catatonic & shivering, dropped 15 pounds or so in about 3 weeks, saw my doctor & got better.) It sounds like the shock or depression you've experience have slowed down your metabolism and if you're a little depressed you may have become somewhat inert, and when you don't move you don't stay warm. If that's true, you might try taking a vigorous daily walk, or turn some good music on and dance around a few times a day. As for food, try a milk shake or chicken soup, something comforting and easy to swallow, but packed with calories, and be sure to stay hydrated even if you're not hungry.
posted by tula at 5:27 PM on March 19, 2006

As far as anorexics getting hairy because they are cold, I read/saw that they get hairy because women also produce testosterone, which ends up stored in their body fat. When they lose a lot of weight very quickly the testosterone re-enters their blood stream at a high enough level to generate side affects like hair growth on the body.

If someone knows better, or has better info, let us know.
posted by hifimofo at 5:59 PM on March 19, 2006

You have lowered your metabolism by starving yourself for 3 weeks. Start eating normally again, get some exercise if you can, and I would bet you'll start to feel like your normal warm self.
posted by ch1x0r at 6:58 PM on March 19, 2006

hifimoho, sorry I didn't have a source for that; it's just something I've always heard. I Googled, and a bunch of sites (example) do say the hair (lanugo) is an attempt at insulation.

Anorexic women tend to not have periods (amenorrhea), which AFAIK is associated with low testosterone levels. This would suggest otherwise, but I'm far from positive about that.

Sorry for the derail, Kosh.
posted by booksandlibretti at 7:06 PM on March 19, 2006

As far as anorexics getting hairy because they are cold, I read/saw that they get hairy because women also produce testosterone

This doesn't seem to explain the lanugo on underweight babies (does it?).
posted by Aknaton at 7:59 PM on March 19, 2006

I used to have very wacky eating habits (thanks to an eating disorder "not otherwise specificied--ie. not anorexia or bulimia). Basically, I ate almost zero fat in my diet and I can tell you that even though I was the same weight that I am now I was cold ALL of the time. I simply could not tolerate the slightest chill in the air, and in fact, I'd often feel cold when people around me were complaining that they were hot.

So yet, I do thin you could be experiencing cold intollerance due to the recent change in your eating habits.
posted by mintchip at 8:10 PM on June 7, 2006