100 lb. Club - When you lose weight, where does it go?




daniela
06-09-2009, 02:35 PM
Not sure if this has been posted before but I found it to be a quick interesting read.


In order to understand the disappearance of body fat, we must enter the world of biochemistry. All fats, whether solid or liquid, exist in chemical form as triglycerides, which consist of a glycerol molecule and three fatty acid chains. Each triglyceride macromolecule's appearance is similar to the letter "E"--with the glycerol being the vertical line and the fatty acids as the three horizontal lines. Many of these triglycerides are stored as droplets of oil within the fat cells that make up the fat tissue located throughout the body. They represent a fuel source to support bodily activities, like gasoline held in a car's fuel tank.

People who are overweight or obese--as roughly 66 percent of American adults are--possess large fat cells brimming with triglyceride fuel. When trimming calories and/or increasing exercise during weight loss, the enzyme hormone-sensitive lipase, located within fat cells, responds to hormonal messages and disassembles triglycerides into their component glycerol and fatty acids. These components then slip out of the fat cells and into the bloodstream, where they are accessible to tissues throughout the body. The liver preferentially absorbs the glycerol and some of the fatty acids--the remainder of which is taken in by muscle.

Once inside liver or muscle cells, the triglyceride ingredients are further disassembled and modified, eventually resulting in large quantities of a compound called acetyl-CoA. Within the cells' mitochondria--the powerhouses of the cells--the acetyl-CoA combines with the compound oxaloacetate to form citric acid. This synthesis kicks off the citric acid cycle (or Krebs cycle), a set of chemical reactions that creates usable energy from fat, protein and carbohydrates. As these mitochondrial activities unfold, they generate carbon dioxide, water and heat, as well as adenosine triphosphate (ATP), an energy-carrying molecule that fuels cellular activities.

The carbon dioxide is then expelled from the lungs during exhalation. The water exits the body as urine and perspiration. The heat that is generated helps to maintain body temperature at a comfortable 98.6 degrees Fahrenheit. And the ATP powers cellular activities that require energy--from moving your muscles during exercise, to maintaining your heart's 100,000-plus beats each day, to digesting each mouthful of food that you swallow and processing nutrients into bodily tissues.



The above article was provided by Lora A. Sporny, adjunct associate professor of nutrition education at Columbia University, and it can be found in original format here.
http://www.scientificamerican.com/article.cfm?id=when-you-lose-weight-wher


kim83
06-09-2009, 02:41 PM
very interesting. thanks for the article. :)

Arctic Mama
06-09-2009, 02:45 PM
I knew the basics, but our bodies are quite fascinating, aren't they?


daniela
06-09-2009, 02:53 PM
I knew the basics, but our bodies are quite fascinating, aren't they?

Absolutely! I somehow made it through HS and college without taking a biology class. Sometimes I wish I had. Maybe I should see if there is a biology for dummies book, just something easy so I can learn the basics.

Delphi
06-09-2009, 03:05 PM
That is an excellent and informative article. Thank you for sharing that with us. :)

Devsmama
06-09-2009, 08:03 PM
Very interesting read, thanks for that.

cfmama
06-09-2009, 08:18 PM
That was so neat! Thank you!

A phat chick
06-10-2009, 02:18 AM
Thanks for sharing that! It was an interesting read!

Michelle (A newbie with no signature yet!)

Tai
06-10-2009, 07:17 AM
This was really fascinating to me; thank you so much for sharing it with us.

daniela
06-10-2009, 07:25 AM
It's pretty cool to learn the science behind it.

Michelle1210
06-11-2009, 02:08 PM
I always wondered about that, I just thought you peed it out that is why they till you drink lots of fluids.......You and me both biology for dummies. ;)

Trazey34
06-11-2009, 06:00 PM
I still say this was a glaring design flaw!!! We're like a Pinto or something LOL We should be able to gobble up whatever we want, and have our bodies take exactly what they need to maintain our health, and then expel the rest.

Of course, with the amount of crap i used to eat, I'd have a giant fire hose coming out of my butt...

wow that's making me laugh, sorry i'm tired LOL

LitChick
06-11-2009, 10:41 PM
That's pretty interesting - thanks for sharing! My husband was asking me that very same thing recently, and I realized I didn't really know.

Creeech
06-12-2009, 10:52 AM
Our bodies are truly fascinating. I was actually wondering about this the other day, I figured the sweat and urination but I knew nothing about the rest. Thanks Daniela :D

daniela
06-12-2009, 03:01 PM
Of course, with the amount of crap i used to eat, I'd have a giant fire hose coming out of my butt...

:rofl::rofl::rofl::rofl::rofl::rofl::rofl::rofl::r ofl::rofl::rofl:

I almost spit out my water when read your comment!!!

L R K
06-12-2009, 03:09 PM
Very interesting, thanks for posting :)