Wednesday, January 13, 2010

Where Does Fat Go When You Lose It?

The first thing to remember is that muscle and fat are two different substances, such that one can not be converted into the other. You need to lose fat and build the muscle. Fat is stored in fat cells (adipocytes) which are located all over the body. Depending on factors such as hormones, genetics, and blood sugar regulation you may have more fat cells in certain areas of the body. You have two different body types when it comes to fat cell location upper body heavy (apple shape)and lower body heavy (pear shape). You are born with a certain number of fat cells which you are stuck with. Having said that there are special occasions when these fat cells can multiply. This can happen first in the womb if mom gains way too much weight, you are overfed as a kid in the growing years, pregnancy, and in extreme obesity. So when we lose or gain fat we do not change the number of fat cells only there size. So the fat cells can increase or shrink like a sponge, but the number remains the same.
Lets take a journey and follow the fat to see where it goes when we lose it. The body primarily uses fat for fuel during our normal physical activities or during prolonged aerobic type activities. When the body needs fatty acids for fuel it is transported out of the fat cell and makes its first stop at the liver. The liver has to breakdown these long chain fatty acids (beta-oxidation) into short little 2 carbon fatty acids (Acetyl-CoA) so it can be easily used as fuel. The next step in our journey transports these short little fatty acids (Acetyl-CoA) to the area of the cell that uses these fats for energy or fuel. The part of the cell that does this is the mitochondria which is the powerhouse of the cell. The mitochondria produces all our energy needs for the muscles to work, brain and heart to function. We can increase the number of mitchondria by increasing muscle mass and aerobic capacity. Now we have more engines to burn more fat for fuel. Once the little fatty acid is transported into the mitochondria it goes into a system called the Kreb Cycle which burns up the fatty acids (oxidation) and produces energy. That's where the fat goes.

Tom Mantos
(732) 219-9636