You exhale it. The opposite happens with trees. They get their mass from inhaling, not the soil.
When we lose weight, where does it go?
31–40 of 131 posts
Re: When we lose weight, where does it go?
#32Earlier quoted context omitted.
Our school did not taught that.
Was this in the US? I went to a very large public middle school and high school in Texas, so our experiences may differ, but it was certainly standard there. (This, of course, varies even district to district, but perhaps my experience isn't as general as I imagined.)
I can't image that the mechanism isn't taught. I mean, this is basic biology that we probably all learned in middle school, and certainly had to learn in chemistry class. But I think we just fail to put 2-and-2 together, even the teachers. I think I was in my late 20s when it dawned on me that I was exhaling the food I ate. But I came to that realization in a matter of seconds based on first principles--principles learned in middle and high school.
Economics is similar. Almost every undergraduate students take economics. And Economics 101 is a pretty simple topic. But very few people learn to "think like an economist", even many economists. I guess alot of subjects are like this--real life isn't like the examples in textbooks, but that doesn't mean the rules and principles don't apply just the same. They do apply. Things can quickly get more complicated than in the textbooks. Perhaps we translate "complicated" to "it doesn't apply" rather than what we should be thinking: it does apply just the same, but so do other dynamics, and the interactions can produce counter-intuitive results.
Re: When we lose weight, where does it go?
#33> Even the 150 doctors, dietitians and personal trainers we surveyed shared this surprising gap in their health literacy. The most common misconception by far, was that fat is converted to energy. The problem with this theory is that it violates the law of conservation of matter, which all chemical reactions obey. For reference, if losing 10 pounds of body weight corresponded meant it was converted to energy complete…
> This is an oversimplification; if digestion was 100% efficient, feces would be sterile.
Generally 10% of energy is conserved when moving from one trophic level to the next. [1]
Re: When we lose weight, where does it go?
#34Earlier quoted context omitted.
> This is an oversimplification It's perhaps the most pernicious misunderstanding of calories on the internet. All calories are not created equal. Even just taking the same ingredient (say, an apple) and preparing it (say, by sticking the apple in a Blendtec Blender vs eating it whole) changes the amount of calories available for absorption.
Is it safe to say that taking an apple and manipulating it without adding anything to it could never INCREASE the calories available? So is the reason that the calorie content in the apple changes in blending due to how difficult (or not difficult) it is to digest?
> could never INCREASE the calories available?
It wouldn't add calories, but it would make more calories available in the sense that your body is able to extract them.
For instance, cooking food makes more calories bio-available.
Re: When we lose weight, where does it go?
#35Earlier quoted context omitted.
> This is an oversimplification It's perhaps the most pernicious misunderstanding of calories on the internet. All calories are not created equal. Even just taking the same ingredient (say, an apple) and preparing it (say, by sticking the apple in a Blendtec Blender vs eating it whole) changes the amount of calories available for absorption.
Is it safe to say that taking an apple and manipulating it without adding anything to it could never INCREASE the calories available? So is the reason that the calorie content in the apple changes in blending due to how difficult (or not difficult) it is to digest?
No, blending it increases the calories available to easily absorb. This is partly why juicers are unhealthy.
Re: When we lose weight, where does it go?
#36Earlier quoted context omitted.
> This is an oversimplification It's perhaps the most pernicious misunderstanding of calories on the internet. All calories are not created equal. Even just taking the same ingredient (say, an apple) and preparing it (say, by sticking the apple in a Blendtec Blender vs eating it whole) changes the amount of calories available for absorption.
Is it safe to say that taking an apple and manipulating it without adding anything to it could never INCREASE the calories available? So is the reason that the calorie content in the apple changes in blending due to how difficult (or not difficult) it is to digest?
Basically. It's similar to how we typically process meat without adding anything to it before eating it, to make it easier to digest and to increase the available calories.
The way we process it is by cooking it.
Re: When we lose weight, where does it go?
#37Relatedly, this is the reverse of how trees get their mass: https://youtu.be/2KZb2_vcNTg
This was my first thought as well. Embarrassing to admit that I didn't realize this until I was told it in my twenties and I never looked at trees the same way again!
Re: When we lose weight, where does it go?
#38Likewise, where does that tree in your backyard come from? It is the product of carbon dioxide and water.
edit: The significance of this thought is when a child is asked where a tree or plant comes from, at least in the US, they inevitably answer the ground when the answer should be rain that falls from the sky and air. With the naive notion a tree comes from the ground we miss the obvious which is the ground doesn't sink when a tree grows from it.
Re: When we lose weight, where does it go?
#39Earlier quoted context omitted.
> This is an oversimplification It's perhaps the most pernicious misunderstanding of calories on the internet. All calories are not created equal. Even just taking the same ingredient (say, an apple) and preparing it (say, by sticking the apple in a Blendtec Blender vs eating it whole) changes the amount of calories available for absorption.
Is it safe to say that taking an apple and manipulating it without adding anything to it could never INCREASE the calories available? So is the reason that the calorie content in the apple changes in blending due to how difficult (or not difficult) it is to digest?
What do you mean by "available"?
Fire was an important technology because it allows us to predigest food, getting more out of eating the same amount of stuff. This certainly does increase the calories available in the ordinary usage of the phrase -- but so does the blender example.
Re: When we lose weight, where does it go?
#40Water and CO2? (And, of course, some other byproducts, but by and large.) I mean, I think this is a well-known answer, no? Sorry I don't mean to sound facetious, I haven't opened the article, so I may be surprised, but I thought this was standard knowledge (at least, it was taught in middle school and high school, even though that's been a while ago for me).
I'd say water and CO2 and urea. Protein is roughly 16% Nitrogen by weight.
I was about to say, excreting water and CO2 leaves you no way at all to get rid of nitrogen.