Tuesday, April 14, 2009

Into Thin Air

When people lose weight, where do the pounds they shed physically go?

I ain't missing you
No matter what I might say

5 comments:

patric said...

sweat and poop, duh.

(my word verification today? katie.)

R.W.McGee said...

Yes, sweat, waste...and also matter to energy conversion. Your car burns gasoline...your muscles burn carbohydrates.

Or so I've been told.

Matthew B. Novak said...

How does matter to energy conversion work? Doesn't there still have to be some actual mass? Like gas burns off and you have emissions... right?

My word verification: strap. Not as good as katie, but also a real word. Strange.

Kendrick Novak said...

It gets lost as heat, that is the emission. Heat.

Nate said...

The process of "burning" calories involves breaking down carbohydrates, fats, and proteins. The fundamental building block of these molecules is carbon, with oxygen, nitrogen, and a few other elements. Your cells use a complex multi step chain of catabolic reactions to reduce these molecules to water (H20) and carbon dioxide (CO2). Water is lost through several routes, including sweat, urine, and via exhalation as water vapor. The carbon dioxide is primarily excreted via exhalation, although there is always some in equilibrium with bicarbonate in the blood in order to regulate blood pH and maintain homeostasis. Excess nitrogen is excreted by the kidneys in urine, as are various other waste products. Defecation actually accounts for very little of the weightloss, as it is composed primarily of the indigestible fraction of food (fiber, etc.) along with sloughed intestinal epithelial cells undergoing regular turnover. And yes, there is certainly radiant heat generated, but this phenomena accounts for a negligible amount of the actual weightloss. Heat is the by-product of the chemical redox reactions taking place, corrosponding to the breaking of chemical bonds as electrons lose energy and settle into less energetic orbits.

While it is certainly true that matter has equivalence with energy, as described by Einstein in his theory of special relativity, examples of when this occurs to any significant degree include:
-Nuclear Fusion
-Matter-Antimatter Anihilation
-Particle-Antiparticle pair production



So yes, weight is indeed lost "into thin air" mainly as exhaled gases.