Truth about white, brown and beige fat
15 May 2017 Author: Peter Rana
Not all fat is created equal.
Whereas white fat has been known to store calories and be linked to weight gain, another type of fat - brown fat – burns calories to generate heat. Unfortunately, brown fat, found mainly in small mammals and human infants, diminishes with age.
But the good news is that researchers* have discovered a new type of fat cell present in adults that also has the capacity to metabolise fat, namely beige fat. Although genetically distinct from brown fat, it’s been found to behave in similar ways, having the ability to burn large amounts of calories.
The real skinny on beige fat.
Both brown and beige fat contain energy-burning mitochondria (organelles that convert fuel into energy). However, unlike brown fat, beige fat cells give off low levels of a particular protein (UCP1) that mitochondria need to burn calories and generate heat. But when muscles are subjected to exercise, a hormone called irisin is produced enabling beige fat cells to turn on high levels of UCP1, which in turn burn calories similar to brown fat.
But here’s the real skinny on beige fat according to lead researcher Bruce Speiegelman, Professor of Cell Biology and Medicine at Harvard Medical School. He advises that irisin, the hormone produced by muscular exercise (like HIT strength training at BodyTech), “specifically stimulates white fat to produce beige fat.”
So muscular exercise through proper strength training may have one more positive outcome – it’s a highly efficient way to burn fat by turning white fat cells that are prone to store calories into the more favourable beige fat that burns them.
* Spiegeman, Bruce et al. Cell, p366-76, July 2012