It’s freezing outside, but don’t despair. That chill might just help you slim down a bit.
A new report published in the medical journal Trends in Endocrinology & Metabolism suggests that varying indoor temperatures to coincide more closely with what’s happening outdoors could be beneficial for weight loss.
How, you ask? Report author Wouter van Marken Lichtenbelt of Maastricht University Medical Center in the Netherlands and his colleagues study how slightly cooler temperatures affect body weight. For example, they found that after exposing 51 young men to the chilly temperatures (around 62 degrees F) of a refrigerated room in the lab over 10 days, the participants got used to the cold and shivered less, even when when the thermostat was lowered to about 60 degrees F. The key to their acclimation, the scientists discovered, was the amount of brown fat the men had.
PHOTOS: Winter Storm Pounds Northeast
Abundant in newborns, and less so in adults, brown fat burns energy rather than storing it, and in the process, generates heat (it’s plentiful in rodents, which can’t shiver to warm up). So-called because of the darker colored mitochondria, the cell’s energy source packed inside, brown fat may be a type of backup body heater. Recent research shows that adults may have more stores of brown fat than previously thought, and scientists have been investigating whether activating it could help with weight loss.
Researchers at the University Hospital of Sherbrooke in Canada, for example, found that simply exposing people to the cold activates brown fat, and that once awakened, this fat can actually start to eat away the white fat that builds up around the hips and elsewhere.
According to the researchers of the latest report, for young and middle-aged people, such non-shivering heat production–from brown fat–can burn away up to 30% of body’s energy, thus contributing to weight loss. So it’s not entirely out of the question that bouts of chilliness can drive this process and melt away pounds.
That suggests that all the heating we have in the winter may not be doing our waistlines any favors. “Indoor temperature in most buildings is regulated to minimize the percentage of people dissatisfied,” write the researchers in their report. “This results in relatively high indoor temperatures in wintertime. By lack of exposure to a varied ambient temperature, whole populations may be prone to develop diseases like obesity. In addition, people become vulnerable to sudden changes in ambient temperature.”
But what about populations like Inuits who live year-round in colder temperatures? Cold-weather populations aren’t known to be the slimmest in the world. It turns out their body types are the result of some adaptations triggered by this physiologic process. Inuits consume a lot of fatty foods because that’s what available. Agriculture is tough in cold climates, so they tend eat more fats and animal protein. Most of that fat, however, isn’t the brown type but white fat that isn’t as metabolically active.
Scientists are actively trying to figure out ways to preserve or boost depots of brown fat, to see if it could be one more ally in the fight against obesity. In the meantime, don’t be so quick to turn up the heat during a cold spell. There’s no need to freeze yourselves indoors, but keeping temperatures a little lower than you’re used to might just help in keeping your weight down.