Could Cold Exposure Really Help You Lose Weight?
Obesity is perhaps best thought of as a disease brought on by the vast changes in our lifestyle that have come with our modern age. However, while it's pretty easy to see how changes in how we eat and how we move have led to us being more susceptible to the over-accumulation of fat, some experts are also pointing their fingers towards another difference between then and now: the fact that we spend much less time in the cold.
Thanks to the invention of central heating, a person who spends most of their time indoors now rarely encounters uncomfortably cold temperatures, and they will usually have plenty of protective garments on when they do. So it isn't a complete shot in the dark to think that our bodies might function more optimally, especially when it comes to maintaining a healthy weight, if we deliberately exposed ourselves to lower temperatures.One former NASA scientist, Ray Cronise, decided to take this theory to the extreme after getting impatient with traditional weight loss. He slept on top of ice packs and without blankets, took colder showers, and wore light clothing all the time, even during his three mile walks in 30°F weather. Combined with a healthy low-calorie diet, his extreme methodology allowed him to lose 27 pounds in 6 weeks; three times the rate at which he'd been losing weight from diet alone!
Many dieters have followed in his footsteps, to the point that workout clothing specifically made to accommodate frozen gel packs and special fat-burning ice vests are now commercially available. So what's the science behind this cool new weight loss trend?
First of all, one has to understand the basic principles of thermodynamics and homeostasis. "Homeostasis" refers to the body's efforts to maintain a state of equilibrium at all times, which includes keeping our body temperature as close as possible to one that is normal for us, which in most people is about 98.6°F (37°C).
Thermodynamics means that the production of heat requires energy, so our body needs to burn calories if it wants to warm us up. When you get extremely cold, it might do this by using involuntary muscle contractions to generate heat, which is what we call shivering. However, before that, you may experience a state of "non-shivering thermogenesis," in which your body simply revs up your metabolism to keep you warmer.
To do this, it may use brown fat, a specialized kind of fat cell also sometimes known as "BAT" or "brown adipose tissue." In contrast to typical white fat, which stores energy in the form of triglycerides, brown fat is packed with mitochondria, and burning white fat to produce heat is its primary purpose.
Babies have a lot of brown fat, presumably since they are so small that it is harder for them to stay warm. Women also tend to have more brown fat than men, presumably for a similar reason. Far more interestingly, lean people have more of it than overweight people do.
This is another one of those instances where we don't quite know the cause from the effect! In other words: does being obese cause your body to get rid of brown fat, since you can now presumably stay warmer because of the insulation of all your white fat, or did you gain weight in the first place partially because your lack of brown fat was causing you to burn less calories than a thin person would?However, all is not lost even if you didn't win the genetic brown fat lottery. Stem cell studies seem to show that exposure to cold can trigger the production of "brown fat" or turn some of our white fat into "beige fat" that has some of the fat-burning properties of brown fat! Some scientists thus think that cold exposure could end up being an important weapon in the war against obesity and metabolic syndrome. Men who were exposed to unusually cold environments were found to be burning up to 400 more calories than they would be in a warmer environment, even if they weren't moving around any more than they normally would. Some research also suggests that a drop in temperature of even five degrees might trigger brown fat to start burning white fat, or that brown fat can be metabolically active even when you aren't in the cold at all, thus increasing your overall BMR.In rat studies, cold exposure has also been found to improve sensitivity to leptin, a "fullness hormone" than many obese people display a resistance to. Cold exposure also has been shown to temporarily improve insulin sensitivity in patients with diabetes.Other potential health benefits of cold exposure may be improved antioxidant status, improved immune system function, and increased testosterone levels (which might increase muscle growth and fat loss in both men and women). However, you should beware that most of these studies used relatively extreme forms of cold exposure; just lowering the temperature of your morning shower probably isn't enough!On the other hand, the release of endorphins and norepinephrine that can be triggered by a cold shower has been tentatively shown to improve symptoms of depression. Many people report feeling energized by colder showers and some people believe that exposing themselves to the cold helps them simply because they believe in the value of forcing themselves to do uncomfortable things.
If you're not up to an all-out ice bath quite yet, taking a colder shower or swimming in a cold pool may indeed a decent place to start. For maximum calorie burn benefits, let your body warm up naturally rather than turning up the heat or hitting the hot tub as soon as you're finished chilling out. You should also beware that your body may try to compensate for any calories burned due to cold exposure by increasing your appetite.
As long as you don't have any medical conditions that could be affected by cold exposure and you don't let yourself get so cold that you experience hypothermia or frostbite, it looks like all you're risking by experimenting with cold exposure as a weight loss strategy is a little unnecessary discomfort. Just make sure you're following a proper diet and exercise plan as well as turning down the heat; even the iciest regime won't burn enough calories to combat unhealthy food choices!