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Why do we eat grains? Thermodynamics

111 点作者 lenazegher大约 12 年前

12 条评论

Irregardless大约 12 年前
&#62; Eating fewer grain products is not synonymous with popular diets like low-carb or gluten-free. It needn’t be borne by commitment to a food movement like paleo.<p>Sure, it doesn't <i>need</i> to be related to the Paleo diet, but that's still where it all stems from. It's the same as any other fad diet or pseudoscience: Come up with some reasonable-sounding claims that take advantage of poor scientific awareness (e.g. <i>10,000 years isn't enough time for humans to adapt to eating grains, so we should eat like cave men instead</i>), then make millions of dollars promoting your diet and selling books to your unquestioning followers.<p>There's a common sentiment among Paleo zealots that they finally need to distance themselves from the irrational underpinnings that started the whole fad (see here[1] for a FAQ by the 'Paleo diet' inventor). The problem arises when they go searching for scientific evidence to support their grain bashing, and then we end up with statements like this:<p>&#62; It can stem from the simple proposition that fruits and vegetables are generally healthier to eat than grains. That’s an argument I’ll cover more deeply in later posts.<p>Oh, how convenient. Save the crux of the argument for another time. We'll all be patiently holding our breath.<p>[1] <a href="http://thepaleodiet.com/paleo-diet-faq/" rel="nofollow">http://thepaleodiet.com/paleo-diet-faq/</a>
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vanderZwan大约 12 年前
"<i>Scholars continue to argue over whether an increase in population made the shift towards agriculture necessary, or a shift towards agriculture caused an increase in population that made a return to a hunter-gatherer society impossible5. In either case, once the neolithic revolution had begun there was no turning back.</i>"<p>This is an entirely different discussion than what the article is about, but why are "scholars" assuming those two factors are the only ones to consider? (assuming they actually are, and this assumption isn't years behind the real debate going on among the scientists)<p>There's evidence suggesting that the first time humans cooperated in groups larger than the default tribe size, it was caused by something completely different: religion[1]. Göbekli Tepe - the oldest known temple in the world - predates agriculture[2]. It wouldn't surprise me at all if religion was the main (if indirect) social driving force behind a lot of these prehistoric changes in lifestyles that resulted in modern human society.<p>[1] <a href="http://www.newscientist.com/article/mg21328562.100-the-god-issue-religion-is-the-key-to-civilisation.html?full=true" rel="nofollow">http://www.newscientist.com/article/mg21328562.100-the-god-i...</a><p>[2] <a href="http://en.wikipedia.org/wiki/G%C3%B6bekli_Tepe" rel="nofollow">http://en.wikipedia.org/wiki/G%C3%B6bekli_Tepe</a>
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fjorder大约 12 年前
Interesting article. Allow me to add a few fun details...<p>Early agriculturalists actually had it much rougher than this article implies for a real kicker of a reason:<p>Wild plants <i>suck</i> as crop plants.<p>Maize was domesticated from a bushy grass called teosinte (Agriculture arose independently in the Americas a little later than in the Middle East). Google that and see how closely it resembles the big juicy corn-cobs you're used to. Where corn has giant cobs crammed with hundreds upon hundreds of big juicy kernals, teosinte has a miserly amount of sad, pathetic, and tiny little kernals. You'd have to grow an entire field full of teosinte to equal the output of a small patch of corn. If a modern farmer saw one of his fields being overgrown with teosinte he'd probably spray it with herbicide. If some contagion wiped out all of our crop plants and we had to go back to wild crops we would be absolutely <i>humped</i> as a species. Now, imagine how difficult it must have been to come up with the idea of settling down and growing crops to live on when the crops you could grow were basically weeds!<p>In fact, teosinte was so far from being a viable crop that some have proposed theories about intermediate steps. For example, consider the Beer (or chicha) theory of civilization! Somehow, somebody discovered that you can ferment teosinte into something that tastes weird and makes you act even weirder. Fun stuff! While teosinte was not a crop you could build a viable farm on, maybe some hunter-gatherers stumbled upon the process of making chicha. At first, collecting wild teosinte would have taken a lot of work. Far too much for the calories yielded. However, they probably had the time for the occasional novelty! Being lazy, these hunter-gatherers probably realized they could scatter some of the seeds they collected in a specific spot, continue their wanderings, and find a much denser patch of wild teosinte in the same spot a year later. They might even have started selecting which seeds to scatter, either fortuitously preferring the smaller ones for flavor or being smart enough to deliberately select the mutants with higher yields to sow for next year. Perhaps the first steps towards agriculture (in the new world at least) were taken by the paleolithic equivalent of frat-boys! Actually, no archaeologist would ever say that. They would instead say, "priests and shamans" used the beer for religious ceremonies. (Hot tip: If archaeologists have no clue what something they find is for, they usually say it has "possible religious significance".) It makes no real difference what their reasons were. In this theory, the selective breeding of teosinte to produce maize can start long before people actually have to rely on maize to supply much in the way of calories. Humankind's urge to get plastered may have ultimately led to civilization!<p>Wait! There's more! Proponents of this theory have also pointed out that beer solves a lot of problems early civilizations probably had. Take water quality for example. If a lot of hunter-gatherer's with no concept of germs or hygiene were to settle next to a river, you can bet that the river would be pretty deadly to drink out of before too long. Fortunately, if you take some water, combine it with grain and ferment it, the result is a tasty fermented beverage that is safe to drink thanks to the wonders of alcohol! (Early fermented beverages probably had a pretty low alchohol content and packed a healthy dose of calories. Perfect for quenching the thirst and nourishing hard working agriculturalists from dawn till dusk!) I could go on for a while...<p>TL;DR - Beer, rather than being an evil byproduct of civilization, may be what gave us both agriculture <i>and</i> civilization! Beer is <i>good</i>.<p>Ham-fisted attempt to tie this back into all-things entrepreneurial: The development of agriculture was a bit of a chicken-and-the-egg problem. You can't have agriculture without crop-plants, but how could we have developed crop plants without agriculture? <i>Beer</i>. Sometimes, something that looks like a total waste of time becomes the foundation of very serious things (TM), such as the whole of human civilization. Thanks to the adderall-fuelled march of progress we now get to see this process play out in a matter of years or even months! Keep your eye on frivolous crap!
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zeteo大约 12 年前
Grains are not special because they started being cultivated more intensively 12,000 years ago. They were eaten long before that [1] and intensive cultivation also applied to veggies [2] and fruits [3] on roughly the same historical time frame.<p>[1] <a href="http://en.wikipedia.org/wiki/Ohalo_II" rel="nofollow">http://en.wikipedia.org/wiki/Ohalo_II</a><p>[2] <a href="http://en.wikipedia.org/wiki/Neolithic_founder_crops" rel="nofollow">http://en.wikipedia.org/wiki/Neolithic_founder_crops</a><p>[3] <a href="http://www.vegparadise.com/highestperch39.html" rel="nofollow">http://www.vegparadise.com/highestperch39.html</a>
jond2062大约 12 年前
It's unfortunate that a lot of people are so quick to write off a low-carb, grain-free, or Paleo approach to eating as just another fad. There is actually an extensive amount of science and research behind the principles.<p>Yes, some folks are riding the "fad train" and profiting handsomely from the current popularity. That is true no matter whether it is a diet, a sports team, or a TV show that is currently en vogue. However, there are quite a few people who are actually focused on the science and evidence behind human nutrition and health.<p>The best book I've come across that dives into the research and nearly every important epidemiological study in the last 200-300 years is Good Calories, Bad Calories by Gary Taubes (<a href="http://amzn.to/149HYzi" rel="nofollow">http://amzn.to/149HYzi</a>). It's not exactly an airplane read and certainly not a "diet" book; however, it completely changed the way I think about nutrition, exercise, disease, and overall health.<p>I would also recommend anything by Loren Cordain or Robb Wolf.<p>Before you make any judgments, do the research.
psidebot大约 12 年前
"Grains produce more calories per acre than almost all other foodstuffs." - While this may be true, there are are a couple caveats.<p>First, the per-acre yields for heritage varietals are much lower than those cited in the article, and I suspect that some crops have improved quite a bit more than others.<p>Second, I would speculate that grains' biggest advantage in neolithic times was storage duration, not mass or volume. Today if we have a crop-killing drought we can transport crops from other regions. It's expensive and inconvenient but not often life threatening. Even as little as a couple hundred years ago, any society dependent on agriculture would need a crop that could be stored for multiple years to protect against drought.
enigmango大约 12 年前
I'm confused about the table in the middle of the article. If rice and corn have the same amount of kcal per 100g (365), and rice has a higher yield per acre than corn (7700lbs vs. 6900lbs), how does rice have a lower Calories per acre number? Is there another conversion I'm not seeing?
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SEMW大约 12 年前
&#62; Food production has been optimized throughout the entirety of human existence. But it has been optimized to solve a problem most people reading this article no longer experience. Society no longer needs more food; it needs healthier food.<p>There is an argument that "most people reading this article" shouldn't be taken in isolation from the rest of the world. The market for food is global. And there is (according to the UN) a worldwide food shortage[1]. Certainly, (inflation-adjusted) food prices now way higher than at any point between 1990 and 2007 (though down from peaks in 2008 &#38; 2011)[2].<p>If demand from first world countries shifts to lower-calorie-per-unit-area foodstuffs, eventually the global cost of a calorie's worth of food will increase, exacerbating any food shortage. (Whether that is a good reason not to move away from grains is a matter for debate -- see the endlessly rehashed arguments whenever someone brings up food shortages as a reason to be a vegetarian).<p>[1] <a href="http://www.guardian.co.uk/global-development/2012/oct/14/un-global-food-crisis-warning" rel="nofollow">http://www.guardian.co.uk/global-development/2012/oct/14/un-...</a><p>[2] <a href="http://www.fao.org/worldfoodsituation/wfs-home/foodpricesindex/en/" rel="nofollow">http://www.fao.org/worldfoodsituation/wfs-home/foodpricesind...</a>
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frozenport大约 12 年前
&#62;There is nothing intrinsic to lunch that demands bread.<p>Lunch demands bread, because trying to get 500 calories without a starch is hard and imbalanced. For example, eating 500 calories of meat is about 50 grams of fat (your done for the day). Eating 500 calories is 10 oranges and a stomach ache. For the modern day, its not thermodynamics, its because grains balance our diets.
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KirinDave大约 12 年前
I can't wait for the followup where the author suggests we all switch to eating crops that cannot possibly be produced in volume for the world's population, then that is handwaved away under the implicit assumption that those people are poor and will probably die of being poor soon anyways.<p>Because that's ALWAYS where food articles lead when the hosting domain contains the word "supplements." It's like a 100% probability.
venomsnake大约 12 年前
I would like to see calories/acre of nuts and olives too - cashew and peanuts and hazelnuts pack quite the energy punch too. They may be comparable. So maybe there were other factors at play why grain was chosen as the primary food source.
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confluence大约 12 年前
Never really thought about food in this way before - great article.<p>Which reminds me. Don't you find it funny how some the most important things to have occurred in history came from the most random places, times and humble beginnings? I find the fact that such little, seemingly innocuous, random events go on to have such an enormous impact upon billions of people centuries into the future absolutely fascinating.<p>For example have you ever wondered what effectively helped end the need for slavery and in turn paved the way for women's rights? The steam engine. Weren't expecting that now then were you?<p>History is random like that.
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