Heard of it? It's been around for quite some time. But who has it, what does it do, and how can I increase mine?
Brown fat is very common in rodents and babies. Not so much in adults. Have you ever heard someone talk about how their extra fat layers are to keep them warm when the weather gets cold? They are hinting at brown fat, but in reality, most of our fatty (adipose) tissue isn't brown fat, it's bubbling white adipose tissue that will not assist in keeping you warm. Good try, though. Rodents have a large volume of brown fat to help them survive in cold months. Babies also have a large percentage of brown fat because they lack the ability to shiver to generate heat when they're cold. Children lost most of their brown fat in the first 2 years of life. As adults we might possess 20-30 grams of brown tissue. To put this in perspective, if you weight 150 pounds, this is equivalent to 68.2 kg, or 68,200 grams. If your percent body fat is 20%, that means you are carrying around 13,640 grams of white adipose tissue... so you can see that 20-30 grams of brown fat is not an awful lot in the grand scheme of things.
It is thought that the amount of brown fat you possess varies with the seasons, and perhaps more so in parts of the globe that have dramatic shifts in temperature over the course of year. While this is directly in line with the theory that brown fat is needed to keep you warm, and thus your body would need more when it's colder and less when it's warmer, we are incredibly good at regulating our temperature. So even if you live in Alaska, and it's winter, the thought is that you would wear more clothing and spend more time inside when the weather turns colder, right? For this reason it's difficult to find dramatic differences in individuals living in different parts of the world. 1. We are working with a super small amount of tissue in any given person and 2. we are great at adjusting what we wear and what we do based upon the weather report.
So what does brown fat do? Well it seems that when we are able to increase the amount of brown fat tissue, we also increase our basal metabolic rate... um yeah! who doesn't want their metabolism to run a little faster while you operate in the same manner?? It also can improve insulin resistance. I don't see this as being a direct relation to the brown fat, but more a result of your body utilizing stored fat and ingested glucose more efficiently because your metabolism is kickin' it at a higher rate. But still a great benefit, especially for those with diabetes or a family history of diabetes.
And finally, how can you increase yours? Best of luck to you. Think about this for a moment... I've told you that it's a component of rodents (to keep warm in the winter) and babies (to keep warm because they don't shiver to generate heat). And then I mentioned how great we are at keeping ourselves super comfortable... so to increase yours even a smidge... you've got to get
UNcomfortable.
You've got to make your body work a little harder to keep warm. I've heard of people that love sleeping in a cold room so they can bundle up under the covers. This isn't going to help you out unless your blanket is lined with ice packs, and in that situation you probably aren't sleeping too well. You could try layering on cold blankets to cool down your body temperature, or others have researched having individuals stand in a cold room or outside (if it's cold) for 10 minutes without activity. While both situations resulted in some weight loss, it's unclear whether it was because the chilling induced production of more brown fat, or if it just made the individuals shiver (which will burn extra calories as your muscles spasm).
What would I do? I would try setting your home temperature a little lower. It may help you to feel a little cooler and stimulate some brown fat production... or it may just result in a lower heating bill. In any case, a lack of brown fat is probably not the major reason that you are overweight, or overfat - but making an effort to stimulate it at least shows you are thinking about making some changes for a healthier you. :)
