Whats with the Kilojules and Cal

5211 · 07-07-2008, 11:17 AM

Does Cal = 1000 calories?

because everyone keeps referring to exercise and daily consumption of energy as calories and not kilo calories

as i understand it

1 calorie = 4.18579999999326 joules
so i with that 4.185 kj should = ~ 1 kilo calorie

but why are the conversions so off on packets of food?

my protein powder says in a 40g serving there is 604kJ and that is equal to 144Cal

arn't they off by a factor of 1000? unless Cal = kilocalorie which doesn't make since because everything else puts a k to represent kilo

This only recently occurred to me when in a lecture, the lecturer said you produce about 1000 kilo calorie of heat in 1 hour of intensive exercise..

and i was like.. that can't be right.. if we consume 2000 cal a day 1000 000 will mean in 1 hour of heat we use up 500 days worth of energy

anyone ever wondered the same thing?

-----------------------------------------
*Edit* found the answer
wasted 10 min on google and only needed a second on wikipedia

At all times on this web page, unless specifically stated otherwise, whenever we are refering to Calories, we are speaking of Food Calories, or what is known as kilocalories in a physics lab.

It is normal convention to use the Capital letter 'C' to begin the world Calorie when refering to Food Calories and we have always attempted to follow that convention.

1 [Food] Calorie = 4180.6 Joules... whereas ur normal calorie has a lower case "c"

**ZackKnight** · 07-07-2008, 11:37 AM

ur a big science guy huh?

5211 · 07-07-2008, 11:45 AM

nevermind found the answer

post *edited*

**AlteredBeast** · 07-07-2008, 12:47 PM

yeah...I was under the impression that a kilo calorie was understood to be equal to 1 normal calorie we see on nutrition labels. Jules? I thought it was spelled Joules?

**AlteredBeast** · 07-07-2008, 12:48 PM

Oh wait...that was just the title to the thread...you may want to edit that.

**Freak** · 07-07-2008, 05:24 PM

You're right AB. Yeah it is confusing 5211.

**Thomas_Rivera** · 07-07-2008, 05:53 PM

I think its more confusing for people who know about the difference between using a Calorie and a calorie.

Like how I never understood why most of the world uses kilograms as a weight when it describes mass.

**mabo** · 07-07-2008, 08:19 PM

What would you prefer they use? Newtons?

**Thomas_Rivera** · 07-07-2008, 08:25 PM

Any force related measurment would be fine with me.

**AlteredBeast** · 07-07-2008, 11:33 PM

Quote:

Originally Posted by mabo

What would you prefer they use? Newtons?

I think our posts flew right over your head. I'm not even going to bother...

5211 · 07-08-2008, 05:46 AM

AB title edited :) so pedantic :P

we use kg because it's the standard

America likes to be different form the rest of the world some reason

adrenaline u guys say epinephrine
testosterone you guys like androgen..

everyone uses meters and cm you like feet and inches

everyone uses kg u like lb

why????????

**ZackKnight** · 07-08-2008, 07:43 AM

he was moreso talking to Rivera is what it looked like.

that's kind of a dick thing to say dude.