Winter brings cold. Muthu Periasamy, PhD, professor at Sanford Burnham Prebys Medical Discovery Institute (SBP) at Lake Nona, studies how muscle burns calories to generate heat and keep our bodies warm. We recently spoke with him about how cold weather can promote weight loss—and why this may not be a perfect strategy to slim down.
How does being cold affect metabolism?
Because we need to keep our bodies at around 98 degrees Fahrenheit, being in a cold environment makes us burn more calories to generate enough heat. That’s why people who live in extremely cold places like the Artic eat high calorie foods like whale blubber—to provide the extra energy needed to maintain their body temperature.
Could living in a cold environment be a way to lose weight?
Theoretically, yes, but realistically, no. People who live in cold parts of the world actually tend to gain weight during the winter because they’re less active.
To lose weight by cold exposure, you’d have to be outside most of the winter or have your thermostat set to something like 40 degrees Fahrenheit. It’s hard to imagine anyone actually doing that. I know I wouldn’t! Plus, if your metabolic rate increases, so does your appetite, so you’d have to be very careful to keep from eating more.
How does your research relate to all this?
We study a protein called sarcolipin. The protein regulates how calcium moves around inside muscle cells—where there’s more sarcolipin, calcium transport generates more heat. We’re trying to figure out how to exploit sarcolipin as a way to increase metabolism for weight loss.
We’d been examining sarcolipin for a long time, but didn’t make the connection to body heat until a few years ago. We learned about the heater organs of deep-sea fish, which evolved from eye muscles. They generate heat by bumping up the activity of their calcium pumps, so we wondered whether muscle in mammals might do something similar.
We made mice that lack sarcolipin, and they couldn’t keep warm when they were exposed to cold for several hours, even though they had brown fat, another tissue that produces heat. That was exciting because it showed that muscle is really important for keeping mammals warm.
How would sarcolipin-targeted therapies work?
We don’t know yet, but any treatment we come up with would have to be combined with exercise. Calcium only moves around in muscle cells when they’re contracting or as a response to cold, and no one would want to live in constant winter!
For more on Periasamy’s research, watch this video: