That's a good article. Perhaps the most telling comment is "Although not
generally realized nutritionists actually have been measuring energy in joules
and thus applying various factors to convert to the various calories. " While
that is a direct quote, it would make more sense as:
Although not generally realized, nutritionists actually have been measuring
energy in joules and then applying various factors to convert to the various
calories.
The calibration process in calorimetry is such that joules are naturally being
measured, and as an extra step, they are converted to calories with whatever
factor the researcher elects to use. If you can find it, the conversion back
to joules is the inverse of whatever he used, out of five or more possible
values. If you use the wrong one, a minor error occurs. But why convert in
the first place? (They are clear the recommended factor is 4.184 kJ/kcal.)
This factoid really punctures the balloon of any debate over the matter.
I guess the US took them a little too seriously when they recommended "gradual
changeover." We have elevated "gradual" to a procrastination artform. Our
nutrition labelling laws require the "nutritional" calorie (some flavor of
kilocalorie), so the law would have to change before the labels can change.
The government seems committed to stonewalling any metrication requirements so
the likelihood can be described as {snowball, hell}.
NOTE: In SP811, NIST gives conversions for all five flavors of nutritional
calorie, perhaps incorrectly, given this recommendation. Fortunately, the
dispersion around the recommended value is (approx) -0.05% to +0.07%, and few
measurements are actually this good.
________________________________
From: Pat Naughtin <[email protected]>
To: U.S. Metric Association <[email protected]>
Sent: Mon, January 4, 2010 9:36:42 PM
Subject: [USMA:46361] Energy measurement in kilojoules
Dear All,
You might be interested in this article that I think comes from 1971.
It appears that the United Nations Food and Agriculture Organisation (FAO) and
the World Health Organisation (WHO) adopted the joule as the SI unit of energy
from 1971. See http://www.fao.org/docrep/meeting/009/ae906e/ae906e17.htm
You can see my thoughts on this topic if you go
to http://metricationmatters.com/why_metrication.html and search for the
heading, 'Energy and power'. By the way, it looks like this page needs an
update as back then (in 2007) I only found 93 different words for old
pre-metric measuring words to obfuscate energy and power issues – my list now
runs to 199 different old words for energy measurements (with a mere 9702
different conversion factors).
Cheers,
Pat Naughtin
Author of the ebook, Metrication Leaders Guide, that you can obtain
from http://metricationmatters.com/MetricationLeadersGuideInfo.html
PO Box 305 Belmont 3216,
Geelong, Australia
Phone: 61 3 5241 2008
Metric system consultant, writer, and speaker, Pat Naughtin, has helped
thousands of people and hundreds of companies upgrade to the modern metric
system smoothly, quickly, and so economically that they now save thousands each
year when buying, processing, or selling for their businesses. Pat provides
services and resources for many different trades, crafts, and professions for
commercial, industrial and government metrication leaders in Asia, Europe, and
in the USA. Pat's clients include the Australian Government, Google, NASA,
NIST, and the metric associations of Canada, the UK, and the USA.
See http://www.metricationmatters.com/ to subscribe.
