There may be a reason that Santa, who spends most of his time toiling away at his freezing North Pole workshop or traversing the globe in an open-air sled, is a little on the rotund side. A bowl full of jelly may actually help to defend people against cold weather — at least to a certain extent.
It’s not the most politically correct of questions to ponder to be sure, but Popular Science recently shed some light onto whether fat people stay warmer in the cold than thin people, and the answer is both yes and no.
According to Popular Science, studies done on both cold-water swimmers and hospital patients have shown that people with a higher Body Mass Index (BMI) are less susceptible to hypothermia because fat insulates the body’s core.
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That’s not surprising, considering that fat certainly plays an important part of thermal regulation in animals. Whales have a layer of blubber that is vital to insulating them against cold water, while camels, which live in hot climates, hold all of their fat in their humps to avoid all-over insulation, reports Discovery Magazine.
In humans, thermoregulation gets a bit more complicated.
Because of complex signaling in the brain in response to cold weather, people with a higher BMI may in fact have the sense of feeling colder.
Here’s how it all works: When the outside temperature drops, our brains trigger our bodies to respond by interpreting two signals, internal body temperature and the temperature on the surface of the skin. According to Scientific American, when blasted with a winter chill, our blood vessels constrict, limiting our heat loss through the skin, and we start to shiver, which warms us up.
But in people with a higher BMI, subcutaneous fat effectively insulates the body’s core, while the skin cools. According to Catherine O’Brien, a research physiologist with the U.S. Army Research Institute of Environmental Medicine, a cooler skin temperature may make obese people feel colder in response.
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Of course, subcutaneous fat isn’t the only factor that affects humans’ temperature. If you are relatively fit and seem to "run hot," there’s an explanation for that: Muscle tissue generates heat, offering a different protection from the cold. If you’re relatively petite, not only does a low BMI heighten your response to cold, but so does your overall surface area. According to O’Brien, smaller people lose heat more quickly.
The combination of lower muscle mass and higher surface area in women provides some much-needed insight about the age-old stereotype that the female population is always cold (so next time the lady in your life asks for your jacket, don’t hesitate to hand it over).
But overall, which is better for handling cold weather, being slightly on the hefty side or thinner?
“We have a joke around here that the person who’s best-suited for cold is fit and fat,” O’Brien told PopSci.
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