[ExI] Calories in/out, grains (of starch), and stable isotope analysis
js_exi at gnolls.org
Sat Jun 18 00:44:25 UTC 2011
The problem with invoking "calories in, calories out" is that the two
quantities aren't independent.
In this article, I walk through an excellent controlled study showing
that isocaloric meals dramatically affect satiety 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.
If you'd like to go through the entire study yourself, it's here:
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 misused 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"
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:
It is apparently quite popular to see references 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:
Stable Isotope Evidence for European Upper Paleolithic Human Diets
Michael P. Richards
"This paper presents the published and unpublished stable carbon and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."
It is certainly possible to argue how much non-protein was eaten and
from where it was obtained...but it's difficult to argue that cereal
grains provided a significant caloric contribution long previous to
agriculture. 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.
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