Who in the world would want more fat on their body?

Well, if it’s brown fat, then almost everyone should!

There are mainly two types of fat in our body – white and brown. I’ll surprise you with a third type later! What is amazing is that these two types of fat have completely opposite functions.


White fat

White adipose tissue is the one that is annoying you and you are constantly trying to burn off and shed.

White fat functions to store excess energy as triglycerides, of course, in all the wrong places! White fat has huge lipid droplets and low numbers of mitochondria, making it very low in its’ energy expenditure. Also, it is a major source of the inflammation which occurs in obese individuals.

For a long time, it was assumed that white fat was the only kind of fat found in adult humans.

Brown fat

Brown fat was assumed to only exist in animals and human infants. One of the major locations of brown fat in mammals , as well as in infants, is their intra-scapular region, or the region between their shoulders, neck, and upper chest.

However, ever since 2009, many studies have shown that adults also have significant amounts of brown fat.

Now this is good news for us, since brown fat dissipates and uses energy. Its function is to produce heat as a defense mechanism against cold, especially in animals which lack the ability to shiver. Infants and young children lack the ability to shiver in response to cold!

Brown fat has a larger number of capillaries than white fat because of its higher oxygen consumption.

Brown fat also has many nerves, providing sympathetic stimulation to the fat cells. Brown adipose tissue has very small lipid droplets and is very high in mitochondria. In fact, it has more mitochondria than any other cells in our body!

Brown fat has been shown in studies to have anti-obesity effects. How is this?

Our body weight is the result of the balance between our energy intake through food, and our energy expenditure. A part of our energy expenditure is used for adaptive thermogenesis, or maintaining our body temperature constant.

brown fat_2

Adaptive thermogenesis is a function preformed by brown adipose tissue through a brown fat specific protein called UCP1, or uncoupling protein 1, which makes the brown adipose tissue inefficient in producing ATP, and as a result the energy produced is generated as heat.

Inverse relationship on your BMI

It is estimated that on average, adult humans have about 50-100 grams of brown fat.

Very interestingly, research has shown that there is a clear inverse relationship between the amount of brown fat and the BMI, or adiposity of an individual, meaning that the leaner you are, the more brown fat you have, compared to your obese counterparts.

Also, the amount of brown fat is age dependent – in their 20’s almost half the population has detectable amounts of brown fat. However, in older individuals, in their 50s and 60s, this number largely decreases. This is an indication of the importance of the role that brown fat plays in energy homeostasis in adults.

Wait.. another form of fat?

Now, for the surprise, there is another intermediate form of adipose tissue which is called beige or brite cells, also known as recruitable or inducible brown fat cells.

These beige cells emerge within white adipose tissue, and can eventually even take over the entire white fat tissue in response to certain environmental conditions such as exposure to chronic cold .

This processes is called browning of white fat, forming beige cells, which take on the characteristics of brown fat, becoming energy burning machines!

And it’s scientifically proven

This process was demonstrated in a study in 2013.

A group of people with minimal amounts of brown fat were exposed to temperatures of 19°C for 2hrs daily, for 6 weeks. At the end of the study, the majority of them had increased amounts of brown fat and their BMI, or adiposity, was significantly reduced due to the increased energy expenditure by newly formed brown fat.

The promising results of this experiment has opened the door for a huge gush of new research which may soon provide us with new obesity treatments.

In the meanwhile, a little cold this winter might not be such a bad idea after all!

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