Can I Activate Brown Fat for Weight Loss?

brown fat for weight loss
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If you read the latest research and weight loss news, then you've read about brown fat. Some studies suggest that if you use cooling methods to activate brown fat you can slim down faster. But before you make plans to freeze your butt off, find out what the research reveals about beige fat, white fat and brown fat for weight loss. 

White Fat vs. Brown Fat to Lose Weight

Several years ago, researchers discovered that many of us have more than one kind of fat cell in our bodies.

We've known about white fat for years. White fat cells are what we typically refer to as body fat. White fat cells store excess energy or calories. When we eat too much, the excess calories are stored as white fat and we gain weight. White fat is the kind of fat that builds up on our thighs, our bellies and our arms that we often try to reduce.  

Brown fat is different. Scientists refer to brown fat cells as brown adipose tissue or BAT. Brown fat cells don't store energy, they burn it. These smaller, complex fat cells actually create heat to maintain your body temperature when it's cold. So this type of fat becomes activated when your body is exposed to cold or even freezing temperatures. Brown fat is often found in the upper back and neck region of the body and researchers think it may hold promise in the fight against obesity.

But the good news doesn't end there. There is a third kind of fat that is relatively new to researchers.

It's called beige fat. Beige fat cells are essentially brown fat cells that reside within white fat tissue. Researchers are beginning to study whether they can learn to activate these beige fat cells to function like brown fat and burn more calories.

Brown Fat for Weight Loss: Does It Work?

The news about brown fat and beige fat is exciting, but I wouldn't move to Alaska, sleep in your refrigerator or attempt other body cooling methods to lose weight just yet.

The most significant brown fat results have been established only in mice. Brown fat research in humans is still inconclusive for a number of reasons.

  • You may not have brown fat.  Many years ago, scientists believed that only babies had brown fat. More recent studies have confirmed that some adults have brown fat, but we don't really know how many people have it or how much they have. One large study found that only 7.5% of women and 3.1% of men had substantial brown fat deposits. Other more limited studies have demonstrated that anywhere from 25% to roughly 80% of people have small brown fat deposits. So how do you know if you have brown fat? Without expensive scanning equipment (a PET scan), you don't. We do know, however, that brown fat decreases with age and that the fatter we are, the less brown fat we have. 
  • Brown fat may not burn enough calories. Researchers also don't know exactly how many calories you can burn when and if you are able to activate brown fat. Some studies estimate that you may be able to burn up to 13%-20% of your resting metabolic rate. For some individuals that may add up to 150 calories or more. But other experts say that the total number is probably only 50-100 calories per day, at most.
  • Scientists advise caution. The most well respected fat researchers still advise caution when it comes to the use of brown fat for weight loss. While current studies provide insight and promise, we still don't know how to activate brown fat in a way that is manageable and sustainable in a real world setting. The bottom line is that we simply don't know if activating brown fat can make a noticeable difference.

If you're trying to lose weight and you've struggled with traditional methods, you might be tempted to activate brown fat in your own body with trendy products like thermal vests or cooling shorts. Try to keep the science in mind as you consider those purchases. The research into brown fat for weight loss is substantial, but it doesn't prove that any brown fat treatment actually works.


Aaron M. Cypess, M.D., Ph.D., M.M.Sc., et al. "Identification and Importance of Brown Adipose Tissue in Adult Humans." New England Journal of Medicine April 9, 2009.

Aaron M. Cypess and C. Ronald Kahn. "Brown fat as a therapy for obesity and diabetes." Cypess AM, Kahn CR. Brown fat as a therapy for obesity and diabetes. Current opinion in endocrinology, diabetes, and obesity. April 2010.

Masayuki Saito, et al. "High Incidence of Metabolically Active Brown Adipose Tissue in Healthy Adult Humans." Diabetes July 2009.

Medscape Diabetes & Endocrinology. Can Brown Fat Play a Role in Weight Loss? Eric Ravussin, PhD. Accessed: August 11, 2015.

Matthew Harms & Patrick Seale. "Brown and beige fat: development, function and therapeutic potential." Nature Medicine September 2013.

Research Matters. Shivering Triggers Brown Fat to Produce Heat and Burn Calories. National Institutes of Health. Accessed: August 11, 2015.

Research Matters. Cool Temperature Alters Human Fat and Metabolism. National Institutes of Health. Accessed: August 11, 2015.

Research Matters. Overlooked “Brown Fat” Tied to Obesity. National Institutes of Health. Accessed: August 11, 2015.

Medscape Diabetes & Endocrinology. Can Brown Fat Play a Role in Weight Loss? . Eric Ravussin, PhD. Accessed: August 11, 2015.

Leon Straub, Christian Wolfrum. "FGF21, energy expenditure and weight loss – How much brown fat do you need? " Molecular Metabolism June 2015.

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