Research seems to highlight the potential of this little-known tissue in the human body as a weight loss dynamo. Brown Adipose Tissue (or Brown Fat) plays a key role in metabolism. A typical person has about ½ oz of it (about 13g), while almost 2 oz (50g) of this tissue could use up to 20% of your calories for the day! Cooler temperatures activate its weight-shedding by causing it to generate body heat, which increases metabolism. But, there is still a lot to learn about Brown Fat and its role of increasing your metabolism and controlling your weight.
The “Bad” Fat and the “Good” Fat
When we think of fat, we invariably think of the stuff around the waist or the hips. In reality, there are two types of Adipose Tissue (Fat), White and the Brown Adipose Tissues. The White Fat is what we commonly try to lose when we try to lose weight by dieting or exercising. It is the most common type of body fat, comprising 20-25% of your body. Its biological function is to store energy – when you eat too much food, excess calories are stored around your waist or hips. As Einstein said, energy can’t simply disappear.
Brown Adipose Tissue has a different mission. Rather than being the storehouse of energy, Brown Fat is actually a key tissue in thermogenesis – the generation of heat by your body. Because of this, Brown Fat actually uses energy like your muscles do, and it is very good at using it. Some research suggests that 50 g of Brown Adipose Tissue can use up to 20% of your typical daily calories (Cypress, A. M., Lehman, S., et al. “Identification and Importance of Brown Adipose Tissue in Adult Humans.” The New England Journal of Medicine (2009): 1509-17.)
Cranking Up the Weight Loss
Here is the not so good news.
- An average human body contains about ½ oz in, and either it disappears or somehow becomes less active over time. The Cypress Study found that the greatest activity of these cells was in people younger than 50, and that people over 64 seem to exhibit substantially less detectable activity by these cells. Similarly there are other causes by which the amount or the activity of Brown Adipose Tissue is reduced (for example, the use of beta-blockers seems to negatively affect its activity).
- Keeping the temperature around normal room temperature (approximately 71-72F, or 22C, or warmer) turns off these cells’ activity (van Marken Lichtenbelt, W.D., Vanhommerig, J. W., et al. “Cold-Activated Brown Adipose Tissue in Healthy Men.” The New England Journal of Medicine (2009): 1500-08.). As was reported in this study, cooler temperature  of around 60F or 16C or less is needed in order to kick start this weight loss dynamo. As temperature drops, your body needs to start generating more heat, which starts to use energy for thermogenesis, (think of your home heater in winter using more energy to keep your house comfortable).
Great… Now what?
As we have maintained all along, losing weight is easy. For those of you blessed of living in a cooler climate – go outside. Take a walk. And, don’t put on your parka. But, take advantage of what nature has given you.
Even those of us that live in warmer climates can take advantage of this. Morning temperatures are frequently cooler by a good amount, and taking advantage of this time makes sense. Exercising in the morning, by simply taking a mild walk, can do wonders for someone who is not currently active. Remember to talk with your healthcare professional before starting any exercise or diet.
However, the bottom line is that Brown Fat Cells (at least as demonstrated by current research) are more of a possibility on the radar screen than a true strategy for weight loss. True weight loss comes from maintaining the correct balance of energy intake (e.g. food eaten) and energy use (e.g. exercise + daily activity). This is where your healthcare provider, in conjunction with a sound program will make the difference in your results, and your ultimate ability to maintain your weight loss.
Additional Resources
Exercise category on 20BMI.com
Metabolism category on 20BMI.com
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