What determines a calorie?

Guitarjon
Guitarjon Posts: 204 Member
edited November 2024 in Food and Nutrition
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.

Replies

  • kennie2
    kennie2 Posts: 1,170 Member
    google is your friend
    dont be scared of it
    it doesnt bite
  • yo_andi
    yo_andi Posts: 2,178 Member
    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.
  • cadaverousbones
    cadaverousbones Posts: 421 Member
    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.
  • Toddrific
    Toddrific Posts: 1,114 Member
    http://en.wikipedia.org/wiki/Calorie
  • shady1987dre
    shady1987dre Posts: 186 Member
    google is your friend
    dont be scared of it
    it doesnt bite
    http://lmgtfy.com/?q=What+determines+a+calorie
  • kunibob
    kunibob Posts: 608 Member
    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.
  • kunibob
    kunibob Posts: 608 Member
    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
  • skywa
    skywa Posts: 889 Member
    its just a unit of energy.
  • adriadawn19
    adriadawn19 Posts: 174 Member
    It is basically how much energy it takes your body to break down the food
  • treetop57
    treetop57 Posts: 1,578 Member
    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.
  • mauryr
    mauryr Posts: 385
    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.
  • treetop57
    treetop57 Posts: 1,578 Member
    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 . . . .
  • treetop57
    treetop57 Posts: 1,578 Member
    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.
    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!
  • healthycurves2012
    healthycurves2012 Posts: 51
    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.
  • kunibob
    kunibob Posts: 608 Member
    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*
  • ATT949
    ATT949 Posts: 1,245 Member
    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?
  • stefjc
    stefjc Posts: 484 Member
    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!
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