In response to my recent post, Trying To Cut Down On Heating Costs? Go Gradually, a commenter wrote, "If I feel a little cold, I just tell myself that I am burning more calories when I am chilly... because that's true." I'd heard this before and always wondered about it, so I finally looked into it...
- ABC News reports that according to a former NASA scientist, "'In environments as mild as 60 degrees, some... people saw metabolism rates boost by as much as 20 percent,' he said." Not bad!
- Of course, they also report that according to proponents of "thermal dieting", "People can burn up to 50 percent more calories by exposing themselves to below-freezing temperatures, which causes the body to work overtime." Keep in mind that this means facing such temperatures without wearing warm clothes, and ask yourself if you'd die 50% more than usual.
- In 2011, the New York Times pointed out that while keeping temperatures cooler can burn slightly more calories, and making the house so cold that you're shivering can burn even more calories, "a person insulated with plenty of body fat is usually less likely to shiver". Also, if you're shivering enough to burn significant calories, you may be on the cusp of hypothermia.
- If you'd like to really get into the numbers, LiveStrong has the formula for calculating your Basal Metabolic Rate, as well as this juicy piece of information: "BMR will change by seven percent for each temperature change of 0.9 degrees Fahrenheit". Keep in mind this is body temperature, not ambient temperature, and it's true for degrees above and below your natural set point (usually 98.6ºF).
- In regards to exercising in cold temperatures, FitSugar reports, "Shivering alone can actually burn up to a few hundred calories an hour, but this effect of cold temperatures on metabolism is only significant if you’re actually shivering. It would have to be very cold to shiver while jogging, because so much body heat is generated from your exercising muscles." Shivering while jogging would be one of my personal hells.
- However, according to a British study described in the New York Times, shivering might not be necessary after all, thanks to a miraculous substance called "brown fat": "“When we put people in a 60-degree room, they increase their energy expenditure by 100 or 200 calories a day if they’re in light clothing.. They’re not shivering. They activate their brown fat.”
This last bit of information is critical, at least for me: in order to burn extra calories, it's not enough to keep our homes at 60ºF or lower. We would need to keep temperatures that cool and only wear light clothing. I might have acclimated to keeping my house at 61ºF (with plans to continuously go lower), but I wear heavy sweatshirts and warm socks. My goal has been to save money and resources, not to lose weight, so I still want to be as warm as possible while keeping the heat as low as possible. If I'm interpreting these studies correctly, in order to lose weight thanks to your home's cool temperature, you need to actually be cold. No, no, no, thank you.
But would it work for you?