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traineo Community / Diet & Nutrition Tips / kcals vs. cals vs. kjoules?
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Courtney
traineo Newbie
Posts: 3
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 # Posted: 22 Aug 2006 21:44


This may be a stupid question, but when I look at traineo's diet recommendation for me and it says 1350 kcals/day, how is that different from plain old cal, or calories? I can't figure out the conversion factor they must be using, because literally 1 kilocalorie should equal 1000 calories... obviously, though I wish I could, I can't be eating 1350000 calories per day! So does anyone know what a kcal is?

Something I thought of was - maybe they meant kjoules? And if that's the case, does anyone know how to convert kjoules to calories, or for that matter kcal (whatever those are)?
James Denham
traineo Regular
Posts: 60
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 # Posted: 22 Aug 2006 21:51


A calorie (cal) is a unit of thermal energy, equivalent to about 4.185 J.

By definition, one calorie is the energy needed to increase the temperature of 1 g of water by 1 °C at 15 °C under normal atmospheric pressure (76 cmHg). In nutrition, it is used to quantify the energy of food and the defining quantity of water is 1 kilogram, making the "food calorie" 1000 times as large as the other calorie. Hence, 1 calorie (nutrition) = 1 kcal = 1000 cal, and it is also called the large calorie.

The calorie is not an SI unit where the joule is the only unit of energy. The kilocalorie is frequently used in chemistry because it is a convenient measure of molar free energy: for example, 1.4 kcal/mol engenders a change in equilibrium by a factor of 10.

From http://www.recipeland.com/facts/Calorie
Percy Hanna
traineo Newbie
Posts: 1
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 # Posted: 22 Aug 2006 22:01


To answer your question, Courtney, food labels in North America incorrectly label calories in food. Strictly speaking, 1 calorie according to nutritional information is actually 1 kcal. I believe in Europe (or it may have been somewhere else), I saw food actually label calories with kcals as the unit. So James' answer above is true, but it can be really confusing to the consumer.

Hope that helps!
Maxwell Lamb
Fitness Guru
Posts: 369
Admin
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 # Posted: 22 Aug 2006 22:03


Good answer, James, and totally right - food 'calories' are actually kilocalories, so we list kcals when we're abbreviating.

Thanks!

Maxwell
Shane Hunter
traineo Newbie
Posts: 1
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 # Posted: 22 Aug 2006 22:30


Hey guys:

So, when, on a food lable, the "calorie" should be construde as "kcal"?

Shane
Courtney
traineo Newbie
Posts: 3
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 # Posted: 23 Aug 2006 04:29


Wow, James and Percy - thank you so much for the information! You are the best!

James, I'm premed... so I guess I should have known the info that you posted! :) I'm sure it'll be covered in Chem one of these days. :)

Percy, I never realized that the term "calorie" is kind of a misnomer. Again, thank you guys! I am so thrilled with the knowledge and involvement of this community.
Nick Richards
traineo Fanatic
Posts: 123
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 # Posted: 24 Aug 2006 16:37


Good scientific answer, James.

As everybody says, a food kcal is a 'calorie' for all intents and purposes.
Martin Singer
traineo Newbie
Posts: 4
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 # Posted: 6 Sep 2006 06:02


To help clarify this a little, a kcal is a Calorie and a calorie remains the same. You should never see Calories without a capital C on a food label.
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