Question for biology geeks

pcastagner

This one has always been at the back of my mind: where does the fat go? I mean specifically, where does it go? If one goes on on bowel rest due to an intestinal condition, fat is lost but there is no pooping, so I assume poop is out.

That leaves flatulence, exhaled gases, and urine and sweat, or some other skin secretion. I'm figuring exhaled gases are the most likely answer, but exactly how does that work?

AbsoluteNG

I'm not understanding your question. I'm assuming you want to know a detailed scientific answer on what your body does with fat after you eat it? Now, that's really hard to explain as you need to have a good understanding of biochemistry. I barely remember anything from biochem when I took the course but I'll post section of the link below below that you might be able to understand.

http://themedicalbiochemistrypage.org/fatty-acid-oxidation.php#mobilization

The primary sources of fatty acids for oxidation are dietary and mobilization from cellular stores. Fatty acids from the diet are absorbed from the gut, packaged into lipoprotein particles called chylomicrons within intestinal enterocytes and then delivered to cells of the body via transport in the blood. Fatty acids are stored in the form of triacylglycerols (triacylglycerides: TAGs or TGs) within all cell but predominantly within adipose tissue. In response to energy demands, the fatty acids of stored TGs can be mobilized for use by peripheral tissues. The release of metabolic energy, in the form of fatty acids, is controlled by a complex series of interrelated cascades that result in the activation of triglyceride hydrolysis. The primary intracellular lipases are adipose triglyceride lipase (ATGL, also called desnutrin), hormone-sensitive lipase (HSL), and lysosomal acid lipase (LAL). LAL is the most important lipase involved in lysosomal lipid metabolism as evidenced by the fact that LAL deficiency results in the significant accumulation of cholesteryl esters in tissues such as the spleen and liver. LAL deficiency is commonly called Wolman disease.

Here's a wiki link. Way easier to read and get a general over view.
http://en.wikipedia.org/wiki/Fatty_acids

tigersword

It's exhaled through breath.

KarenJanine

In short it's eventually broken down into carbon dioxide (which is exhaled) and water (which comes out in sweat and urine).

AbsoluteNG

Keytones are also a byproduct, you pee that out.

tbrain1989

thats a bit like asking what happens to fuel when used by your car? essentially fat is an energy store and is converted for use by the body, most commonly to glycogen for energy in muscle contractions (all muscles including your brain and heart) what is left is the waste products. namely carbon dioxide and water, the carbon dioxide is exhaled and the water is released mainly through urine but also in perspiration.

pcastagner

Thanks guys!


I was thinking along the lines of listing all the elements on a fat cell and simply where they wind up in the end.


I'm not well versed on the technical aspects, so basically the conceptual version is good enough for me, with highlights of the coolest mechanisms.