Q for more scientifically knowledgeable folks

[TheCalvinator24]

Is there such a thing as a Calorie?

When we say something "has X Calories" is that really accurate language?

[themanintheseersuckersuit]

Calories / Energy Measurement

A calorie is a unit of measurement for energy. Many different definitions for the calorie emerged during the 19th and 20th centuries. They fall into two classes:

* The small calorie or gram calorie approximates the energy needed to increase the temperature of 1 gram of water by 1°C. This is about 4.184 Joules.
* The large calorie or kilogram calorie approximates the energy needed to increase the temperature of 1 kg of water by 1°C. This is about 4.184 kJ, and exactly 1000 small calories.

In scientific contexts, the name "calorie" refers strictly to the gram calorie, and this unit has the symbol cal. SI prefixes are used with this name and symbol, so that the kilogram calorie is known as the "kilocalorie" and has the symbol kcal. In America, a colloquial usage for nutrition and food labeling uses the term "calorie" to refer to the kilogram calorie. The energy content of food is usually given on labels for 100 g and for a typical serving size.

The amount of food energy in a particular food could be measured by completely burning the dried food in a bomb calorimeter, a method known as direct calorimetry. However, the values given on food labels are not determined this way, because it overestimates the amount of energy that the human digestive system can extract, by also burning dietary fiber. Instead, standardized chemical tests and an analysis of the recipe are used to estimate the product's digestible constituents (protein, carbohydrate, fat, etc.). These results are then converted into an equivalent energy value based on a standardized table of energy densities:

[TheCalvinator24]

So, the answer would be?

[gsabc]

Short version: Yes, there is such a thing. A food calorie is a kilocalorie in standard scientific nomenclature. If you really want to figure out complete input-output thermodynamics of what you eat vs. the energy your body uses in staying alive, you'd multiply your intake of food calories by 1000.

Why in the name of all that's holy you would WANT to do such a thing is more than my feeble brain can comprehend.

[Bob Juch]

Is there such a thing as a Calorie?

When we say something "has X Calories" is that really accurate language?

It's more accurate to say food "has X Calories of potential energy".

[christie1111]

That enough, or do you want more?

[TheCalvinator24]

I guess I have an answer. I'm not trying to stir something up. I admit that I sometimes ask questions with ulterior motives, but this was a pure quest for knowledge. I know I could have googled, but I figured somebody here wold give me a quicker and more concise and precise answer.

[MarleysGh0st]

So, the answer would be?

So, the answer is that the phrase may be imprecise or incomplete, in a scientific sense, particularly if one were doing an Einsteinian discussion of E = MC^2, but it's correct in its colloquial sense, when used to describe the amount of energy in some food being consumed.

IANAL, so you legal eagles may say differently.

[TheCalvinator24]

So, the calorie is a measure of potential energy, right?

[TheCalvinator24]

BTW, I don't even know why this question popped into my head this morning. I'm not dieting or doing anything related to food energy.

[christie1111]

I guess I have an answer. I'm not trying to stir something up. I admit that I sometimes ask questions with ulterior motives, but this was a pure quest for knowledge. I know I could have googled, but I figured somebody here wold give me a quicker and more concise and precise answer.

When they measure calories, they actually 'burn' the food item and measure the amount of energy released. It is in theory the amount of energy produced if you ate it.

You can say you ate X calories. Your body still has to convert them to energy though.

That help?

[Bob Juch]

So, the calorie is a measure of potential energy, right?

No, it's a measure of heat. The food contains potential energy but it has to be "burned" first.

[TheCalvinator24]

Now I'm confused.

[MarleysGh0st]

So, the calorie is a measure of potential energy, right?

No, it's a measure of heat. The food contains potential energy but it has to be "burned" first.

But as Cal is staring at that cookie in front of him, it is potential energy, expressed in the chemical bonds of the sugars and carbohydrates it's made with. When he eats that cookie and goes running to burn it off, those substances are digested and converted into heat, unless he doesn't go running, in which case that cookie may be converted into fat, when it again is a potential energy to be burnt off at some later time.

By strict definition, a calorie is a measure of heat.

[MarleysGh0st]

Now I'm confused.

You're welcome!

[TheCalvinator24]

So, the calorie is a measure of potential energy, right?

No, it's a measure of heat. The food contains potential energy but it has to be "burned" first.

But as Cal is staring at that cookie in front of him, it is potential energy, expressed in the chemical bonds of the sugars and carbohydrates it's made with. When he eats that cookie and goes running to burn it off, those substances are digested and converted into heat, unless he doesn't go running, in which case that cookie may be converted into fat, when it again is a potential energy to be burnt off at some later time.

By strict definition, a calorie is a measure of heat.

I'm trying to wrap my brain around this. It seems like it is incorrect to say the cookie has or contains a certain number of calories.

[silvercamaro]

I think you are getting hung up on the fact that a measure of something is an abstract concept. All measures are abstract, but if you accept that "an inch" is "a thing" with commonly shared meaning, then "a calorie" also has meaning, even though you cannot see it or touch it.

[TheCalvinator24]

I think you are getting hung up on the fact that a measure of something is an abstract concept. All measures are abstract, but if you accept that "an inch" is "a thing" with commonly shared meaning, then "a calorie" also has meaning, even though you cannot see it or touch it.

But we don't say that something has a certain number of inches.

I think I understand what a calorie is, but it really seems like the common usage is wrong.

[MarleysGh0st]

I'm trying to wrap my brain around this. It seems like it is incorrect to say the cookie has or contains a certain number of calories.

Well, those verbs are being used a little more loosely than in a strict sense of being or ownership. It's not exactly the same as saying that cookie weighs two ounces or contains six chocolate chips. But it's much simpler to to say (and understand in its everyday usage) that the cookie has 100 calories than to say that a human being will gain 100 calories by consuming said cookie.

[Bob Juch]

I think you are getting hung up on the fact that a measure of something is an abstract concept. All measures are abstract, but if you accept that "an inch" is "a thing" with commonly shared meaning, then "a calorie" also has meaning, even though you cannot see it or touch it.

But we don't say that something has a certain number of inches.

I think I understand what a calorie is, but it really seems like the common usage is wrong.

The calories are there, waiting to be released.

[kusch]

I think you are getting hung up on the fact that a measure of something is an abstract concept. All measures are abstract, but if you accept that "an inch" is "a thing" with commonly shared meaning, then "a calorie" also has meaning, even though you cannot see it or touch it.

Huh??? I have a "thing" that could be described as an "inch". I can see it and touch it.

[silvercamaro]

But we don't say that something has a certain number of inches.

Sure we do. A foot has 12 inches. A yard has 36 inches. Sometimes we say there are 12 inches in a foot, just as we sometimes say that there are 100 calories in a cookie.

[Bob Juch]

I think you are getting hung up on the fact that a measure of something is an abstract concept. All measures are abstract, but if you accept that "an inch" is "a thing" with commonly shared meaning, then "a calorie" also has meaning, even though you cannot see it or touch it.

Huh??? I have a "thing" that could be described as an "inch". I can see it and touch it.

My condolences.

[Bob Juch]

So, the calorie is a measure of potential energy, right?

No, it's a measure of heat. The food contains potential energy but it has to be "burned" first.

But as Cal is staring at that cookie in front of him, it is potential energy, expressed in the chemical bonds of the sugars and carbohydrates it's made with. When he eats that cookie and goes running to burn it off, those substances are digested and converted into heat, unless he doesn't go running, in which case that cookie may be converted into fat, when it again is a potential energy to be burnt off at some later time.

By strict definition, a calorie is a measure of heat.

No, those calories will generate energy one way or the other. Excess energy will be used to make fat cells bigger.

[Beebs52]

Idiom. Vernacular. Like that.