- 2011.01.04, 14:32
- "[...] let’s say you’re carrying around 40 pounds of excess fat and you put on that 40 pounds over the course of 20 years, as many of us do. When you’re in your late 20s, say, you’re still lean, and then, lo and behold, you celebrate your fiftieth birthday and you’re obese and your doctor is lecturing you on eating less and getting to the gym regularly (and probably writing you a prescription for Lipitor, as well). Now, if you gain 40 pounds of fat over 20 years, that’s an average of two pounds of excess fat accumulation every year. Since a pound of fat is roughly equal to 3500 calories, this means you accumulate roughly 7000 calories worth of fat every year. Divide that 7000 by 365 and you get the number of calories of fat you stored each day and never burned – roughly 19 calories. Let’s round up to 20 calories, so we have a nice round number. [...]"
So now the question: if all you have to do to become obese is store 20 extra calories each day on average in your fat tissue — 20 calories that you don’t mobilize and burn — what does overeating have to do with it? And why aren’t we all fat? Twenty calories, after all, is a bite or two of food, a swallow or two of soda or fruit juice or milk or beer. It is an absolutely trivial amount of overeating that the body then chooses, for reasons we’ll have to discuss at some point, not to expend, but to store as fat instead.
[...]
The reason people believe we get fat because of overeating and sedentary behavior is because they believe the laws of thermodynamics somehow dictate this to be true. In particular the first law, which tells us that energy is conserved, so if a system takes in more energy than it expends, the energy contained in the system has to increase. If that system happens to be our fat tissue, than the fat tissue accumulates fat. That’s the logic. So if we eat more than we expend, we get fatter and the logic turns this around to say that we get fat because we eat more than we expend. And so, overeating and sedentary behavior are the causes. This is the logic that leads virtually every government health agency and independent health organization (the AHA, the AMA, you name it) to have some variation of this World Health Organization statement on its website or in its promotional material: “The fundamental cause of obesity and overweight is an energy imbalance between calories consumed on one hand, and calories expended on the other hand.”
[...]
Say instead of talking about why fat tissue accumulates too much energy, we want to know why a particular restaurant gets so crowded. Now the energy we’re talking about is contained in entire people rather than just the fat in their fat tissue. Ten people contain so much energy; eleven people contain more, etc.. So what we want to know is why this restaurant is crowded and so over-stuffed with energy (i.e., people) and maybe why some other restaurant down the block has remained relatively empty — lean.
If you asked me this question — why did this restaurant get crowded? — and I said, well, the restaurant got crowded (it got overstuffed with energy) because more people entered the restaurant than left it, you’d probably think I was being a wise guy or an idiot. (If I worked for the World Health Organization, I’d tell you that “the fundamental cause of the crowded restaurant is an energy imbalance between people entering on one hand, and people exiting on the other hand.”) Of course, more people entered than left, you’d say. That’s obvious. But why? And, in fact, saying that a restaurant gets crowded because more people are entering than leaving it is redundant –saying the same thing in two different ways – and so meaningless.
Now, borrowing the logic of the conventional wisdom of obesity, I want to clarify this point. So I say, listen, those restaurants that have more people enter them then leave them will become more crowded. There’s no getting around the laws of thermodynamics. You’d still say, yes, but so what? Or at least I hope you would, because I still haven’t given you any causal information. I’m just repeating the obvious.
This is what happens when the laws of physics (thermodynamics) are used to defend the belief that overeating makes us fat. Thermodynamics tells us that if we get fatter and heavier, more energy enters our body than leaves it. Overeating means we’re consuming more energy than we’re expending. It’s saying the same thing in a different way. (In 1954, the soon-to-be-famous — and often misguided, although not in this case — nutritionist Jean Mayer said that to explain obesity by overeating was about as meaningful as explaining alcoholism by overdrinking, and merely reaffirmed, quite unnecessarily, the fact that the person saying it believed in the laws of thermodynamics.) Neither happens to answer the question why. Why do we take in more energy than we expend? [...]
Answering the “why” question speaks to actual causes. In the restaurant analogy, okay, maybe this restaurant has particularly great food, or it’s happy hour; the drinks are cheap. Maybe it’s pouring outside so a lot of people ran into the restaurant to stay dry. Maybe [...] Maybe [...] Maybe [...].
All these would be valid answers to the question we asked. Some speak to the conditions inside the restaurant (the quality of the food, the price of the drinks, celebrity customers); some speak to conditions immediately outside (a rain storm, no competition, the theater schedule). They all provide the causal information we’re seeking. They answer the “why” question. That more people are entering than leaving doesn’t. It’s what logicians call “vacuously” true. It’s true, but meaningless. It tells us nothing.
[...]
As for the great majority of experts who say (and apparently believe) that we get fat because we overeat or we get fat as a result of overeating, they’re the ones making the junior-high-school-science-class mistake: they’re taking a law of nature that says absolutely nothing about why we get fat and assuming it says all that needs to be said. This was a common error in the first half of the 20th century. It’s become ubiquitous since.
[...] - 85 rakstair doma
- 4.1.11 18:49 #
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Nu jā, bet tu atbildot bišķi sasteidzi...
"Tāpēc, ka kāds par daudz rij ogļhidrātu saturošus produktus. Un tie
ogļihdrāti beigās aizies uz tauku sintēzi."
Jautājums ir kāpēc tas otrs, caurbira, sanāk rij ļoti daudz (piemēram, 300 gramus cukura dienā), bet viņam no tā nekas nav - viņam tas nav "PAR DAUDZ".
"Cilvēks ar lēno vielmaiņu nedrīkst ēst tik daudz, cik cilvēks ar ātro" - uzdevums ir nosakaidrot, kas tieši ir tas cilvēka ģenētiskajā uzbūvē, kas var vielmaiņu paātrināt.
šo uzdevumu jau šobrīd risina... tipa uz šo virzienu http://www.sciencedaily.com/releases/2010/04/100419162308.htm - Atbildēt
