[ExI] Calories in/out, grains (of starch), and stable isotope analysis
J. Stanton
js_exi at gnolls.org
Thu May 12 07:41:07 UTC 2011
[Resending due to the mysterious post-eater that strikes whenever I
haven't said anything for several days. Expect an earlier-dated
duplicate of this to show up 6-8 weeks hence, if the past is any guide.]
The problem with invoking "calories in, calories out" is that the two
quantities aren't independent. Nor is a calorie a calorie.
In this article, I walk through an excellent, tightly controlled study
showing that isocaloric meals dramatically differ in their effects on
satiety, metabolic markers, and subsequent calorie intake.
Specifically, high-carb, low-fat, low-protein meals lead to
substantially greater hunger and subsequent caloric intake than
lower-carb, higher-fat, higher-protein meals.
http://www.gnolls.org/2052/how-heart-healthy-whole-grains-make-us-fat/
If you'd like to go through the entire study yourself, it's here:
http://pediatrics.aappublications.org/cgi/content/full/103/3/e26
Next up: Since the "when did pre-agricultural humans eat" subject has
come up a couple times recently, I believe this is relevant.
This paper has been heavily misinterpreted by the New York Times (and
countless other pop-sci treatments) to claim that pre-agricultural
humans relied upon cereal grains:
"Thirty thousand-year-old evidence of plant food processing"
http://www.pnas.org/content/107/44/18815.full
Note that of the nine detected plant remains, only one is a grain -- of
a bunchgrass, not of any plant subsequently cultivated by humans. All
the others are roots and rhizomes, plus one sedge seed. See this table:
http://www.pnas.org/content/107/44/18815/T1.expansion.html
It is apparently quite popular to see references in the scientific
literature to "starch grains" and mistake that to mean "cereal grains".
Also there is the evidence of stable isotope analysis:
Vertebrate Paleobiology and Paleoanthropology, 2009, 251-257, DOI:
10.1007/978-1-4020-9699-0_20
Stable Isotope Evidence for European Upper Paleolithic Human Diets
Michael P. Richards
http://www.springerlink.com/content/n2871q7u63170045/
"This paper presents the published and unpublished stable carbon and
nitrogen isotope values for 36 European Upper Paleolithic humans from 20
sites. The isotope data were measured to determine the sources of
dietary protein in Upper Paleolithic diets; **** the evidence indicates
that animal, not plant, protein was the dominant protein source for all
of the humans measured. **** Interestingly, the isotope evidence shows
that aquatic (marine and freshwater) foods are important in the diets of
a number of individuals throughout this period."
Again, Ohalo II provides the first evidence of significant grain
consumption, ~18 Kya...and agriculture didn't spread beyond a small
region of the Middle East until thousands of years after its initial
invention ~12 Kya.
JS
http://www.gnolls.org
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