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TOPIC: What determines a calorie?

 
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March 21, 2012 1:37 PM
Is it how hard the food is to break down in the body?

Eg a piece of lettuce is predominantly made from water so is easy to break down which is why it's low in calories?

Just my hypothesising and looking into things really. Answers would be interesting to read.
  11819062
March 21, 2012 1:39 PM
google is your friend
dont be scared of it
it doesnt bite
  4164508
March 21, 2012 1:42 PM
A calorie is a numerical designation of how much energy your body requires to convert a unit of food to a unit of fuel. So yes, because there are fewer nutrients to extract from a piece of lettuce, or physical make-up of lettuce is different from say, a potato's, it has a lower caloric value.
March 21, 2012 1:42 PM
http://en.wikipedia.org/wiki/Calorie

Apparently I food calorie is the amount of energy it takes to increase the temperature of 1 kilogram of water by 1 degree C.
March 21, 2012 1:43 PM
http://en.wikipedia.org/wiki/Calorie
March 21, 2012 1:43 PM
QUOTE:

google is your friend
dont be scared of it
it doesnt bite

http://lmgtfy.com/?q=What+determines+a+calorie
  13777345
March 21, 2012 1:44 PM
It does have to do with how it is metabolized by the body. High-fibre foods aren't as easily as absorbed, so you're bang on the money there.
March 21, 2012 1:45 PM
QUOTE:

http://en.wikipedia.org/wiki/Calorie

Apparently I food calorie is the amount of energy it takes to increase the temperature of 1 kilogram of water by 1 degree C.


1 g, not 1 kg! <--sorry, I will forever be the class nerd who enjoys correcting teacher and such
March 21, 2012 1:47 PM
its just a unit of energy.
March 21, 2012 1:55 PM
It is basically how much energy it takes your body to break down the food
  12514253
March 21, 2012 1:56 PM
QUOTE:

QUOTE:

http://en.wikipedia.org/wiki/Calorie

Apparently I food calorie is the amount of energy it takes to increase the temperature of 1 kilogram of water by 1 degree C.


1 g, not 1 kg! <--sorry, I will forever be the class nerd who enjoys correcting teacher and such


No. The key word was "food" in "food calorie." The commonly used calorie when talking about food is actually 1000 of the calories that scientists use. A scientific calorie is the amount of energy to increase a gram of water 1 degree C. But a food calorie is 1000 scientific calories, or 1 kcal, or the amount of energy to increase 1 kilogram of water 1 degree C.
  13285248
March 21, 2012 1:59 PM
Not to gild the lily, but 1 gram water = 1 cubic centimeter of water. So, 1cal is the amount of energy it takes to raise the temp of 1 cm^3 by 1 degree C.
  2330587
March 21, 2012 2:06 PM
And if you really want to get technical, you also have to specify a particular base temperature and pressure since the specific heat is a function of temperature and pressure as well depending on the material!

But I digress . . . .
Edited by treetop57 On March 21, 2012 2:07 PM
  13285248
March 21, 2012 2:11 PM
QUOTE:

Is it how hard the food is to break down in the body?


No. It's an estimate of how much energy the body would get from a specific amount of a particular food. It's actually measured by burning the food in an instrument called a "bomb calorimeter" and seeing how much energy is generated when the food is reduced to ashes. Obviously your body does something different from actually igniting the food and burning it to ashes, but the estimate is close enough for dieting purposes.

QUOTE:

Eg a piece of lettuce is predominantly made from water so is easy to break down which is why it's low in calories?


No. A piece of lettuce is predominately water so it has very little fuel in it so it produces very little energy if you burn it up. There is a reason that the ancient Greeks and Romans burned oil lamps, not lettuce lamps!
  13285248
March 22, 2012 7:11 AM
Fat is 9 calories per gram, while protein and carbs are each 4 calories per gram. Calories have nothing to do with the way the food is digested.
Edited by healthycurves2012 On March 22, 2012 7:11 AM
March 23, 2012 1:18 PM
QUOTE:

QUOTE:

QUOTE:

http://en.wikipedia.org/wiki/Calorie

Apparently I food calorie is the amount of energy it takes to increase the temperature of 1 kilogram of water by 1 degree C.


1 g, not 1 kg! <--sorry, I will forever be the class nerd who enjoys correcting teacher and such


No. The key word was "food" in "food calorie." The commonly used calorie when talking about food is actually 1000 of the calories that scientists use. A scientific calorie is the amount of energy to increase a gram of water 1 degree C. But a food calorie is 1000 scientific calories, or 1 kcal, or the amount of energy to increase 1 kilogram of water 1 degree C.


Hmmm, now I have to calculate how many calories are in a humble pie. *chomps down*
March 23, 2012 1:25 PM
QUOTE:

Is it how hard the food is to break down in the body?

Eg a piece of lettuce is predominantly made from water so is easy to break down which is why it's low in calories?

Just my hypothesising and looking into things really. Answers would be interesting to read.


Isn't that on the O level syllabus any more?
  3140117
March 23, 2012 1:29 PM
O levels?

Someone else my age then :)

GCSEs nowadays and no, it isn't. I teach A level PE and have to explain this one in detail every year!
  9074298

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