Information like this is a great demonstration of the insanity of traditional CICO dieting.
However, I just want to clarify one point that based on everything I've been hearing about the number of hormones excreted by white fat, Dr. Adam Nally recently stated that there are currently 27 different hormones, I would amend the first 2 lines of the summary to limit the comparison between white and brown fat to their metabolic activity only.
- White fat is metabolically inactive, associated with energy storage, and does not affect the metabolic rate, but is an active component of the endocrine system through the expression of many different hormones.
- Brown fat has lots of mitochondria and is metabolically active, tends to be associated with heat generation (it actually burns glucose, just like muscle) and increase of metabolic rate.
In the Secret Life of Fat book, the author recounts the story of a child that could not gain weight and had everyone stumped until they discovered that she had so much brown fat that everything she ate was literally being burned up by the brown fat before it could be used for maturation. It's certainly an extreme case, but a great example of how metabolically active brown fat can be.