Anyone know how the number of calories in the different kinds of food are
measured . Is it chemical,heat or other .
No one seems to be able to tell me.

If I remember my science from school. a calorie is the amount of energy
needed to raise 1 cubic cm of water one degree.... or something like
that. I really don't know how they measure it for food.
Oh don't quote me on that formula High School was a loooooong time ago.
Connie TC

Andy Petro wrote:
> Anyone know how the number of calories in the different kinds of food are
> measured . Is it chemical,heat or other .
> No one seems to be able to tell me.
>
>

--
Connie TenClay NATA 252
http://home.new.rr.com/tenclay/connie

On Wed, 11 Aug 2004 16:45:56 -0400, "Andy Petro"
> wrote:

>Anyone know how the number of calories in the different kinds of food are
>measured . Is it chemical,heat or other .
>No one seems to be able to tell me.
>
Many science textbooks will go into this.

Calorie is a measure of heat energy that is possible from the chemical
energy stored in that material.

A heat calorie, usually with a small "c", is the energy required to
raise 1 gram of water 1 degree Centigrade at normal atmospheric
pressure.

A food calorie, usually with a large "C", is 1000 heat calories, also
a kcal.

Every chemical reaction will either absorb energy, called endothermic,
or release energy, called exothermic. Digestion of food releases the
stored energy in the food.

As a general rule, carbohydrates and proteins contain about 4 Calories
per gram, and fats and oils contain about 9 Calories per gram. Other
food ingredients do not contain usable calories, except for things
like alcohol (roughly 7 Calories per gram).

From this, you can look at the total grams of carbohydrates, fats, and
proteins in a serving of food, and calculate the total Calories for
that.

Further, your body digests the food, and converts it first to sugar in
the form of glucose or fructose (the simplest forms of sugar). Some of
this sugar is used right away by cells needing energy, some is stored
in the liver and muscles as glycogen, and the rest is stored as body
fat.

In other words, body fat does not come from specific types of food,
but from consuming more Calories than are used by your normal
metabolism plus exercise.

Also, burning food will release the same number of calories as one
could get from digesting it, and this is one traditional tool used to
assess the composition of a food or other material.

How did the energy get into the food in the first place? It is all
solar energy, stored in plants, or plant energy eaten by animals, and
stored in them.

HTH,
Happy trails,
Gary (net.yogi.bear)
------------------------------------------------
at the 51st percentile of ursine intelligence

Gary D. Schwartz, Needham, MA, USA
Please reply to: garyDOTschwartzATpoboxDOTcom

On Wed, 11 Aug 2004 16:45:56 -0400, "Andy Petro"
> wrote:

>Anyone know how the number of calories in the different kinds of food are
>measured . Is it chemical,heat or other .
>No one seems to be able to tell me.
>
Many science textbooks will go into this.

Calorie is a measure of heat energy that is possible from the chemical
energy stored in that material.

A heat calorie, usually with a small "c", is the energy required to
raise 1 gram of water 1 degree Centigrade at normal atmospheric
pressure.

A food calorie, usually with a large "C", is 1000 heat calories, also
a kcal.

Every chemical reaction will either absorb energy, called endothermic,
or release energy, called exothermic. Digestion of food releases the
stored energy in the food.

As a general rule, carbohydrates and proteins contain about 4 Calories
per gram, and fats and oils contain about 9 Calories per gram. Other
food ingredients do not contain usable calories, except for things
like alcohol (roughly 7 Calories per gram).

From this, you can look at the total grams of carbohydrates, fats, and
proteins in a serving of food, and calculate the total Calories for
that.

Further, your body digests the food, and converts it first to sugar in
the form of glucose or fructose (the simplest forms of sugar). Some of
this sugar is used right away by cells needing energy, some is stored
in the liver and muscles as glycogen, and the rest is stored as body
fat.

In other words, body fat does not come from specific types of food,
but from consuming more Calories than are used by your normal
metabolism plus exercise.

Also, burning food will release the same number of calories as one
could get from digesting it, and this is one traditional tool used to
assess the composition of a food or other material.

How did the energy get into the food in the first place? It is all
solar energy, stored in plants, or plant energy eaten by animals, and
stored in them.

HTH,
Happy trails,
Gary (net.yogi.bear)
------------------------------------------------
at the 51st percentile of ursine intelligence

Gary D. Schwartz, Needham, MA, USA
Please reply to: garyDOTschwartzATpoboxDOTcom

Gary S. wrote:

> A heat calorie, usually with a small "c", is the energy required to
> raise 1 gram of water 1 degree Centigrade at normal atmospheric
> pressure.

Exactly. I vaguely remember they turn whatever into a slush and burn
it. Then they see how many degrees the water is. I think. Ask in
rec.food.cooking, there may (I don't know it's been a while) be a fellow
named Shankar there who's a food chemist.

B/

Gary S. wrote:

> A heat calorie, usually with a small "c", is the energy required to
> raise 1 gram of water 1 degree Centigrade at normal atmospheric
> pressure.

Exactly. I vaguely remember they turn whatever into a slush and burn
it. Then they see how many degrees the water is. I think. Ask in
rec.food.cooking, there may (I don't know it's been a while) be a fellow
named Shankar there who's a food chemist.

B/

Brian Mailman wrote:
> Gary S. wrote:
>
>> A heat calorie, usually with a small "c", is the energy required to
>> raise 1 gram of water 1 degree Centigrade at normal atmospheric
>> pressure.
>
>
> Exactly. I vaguely remember they turn whatever into a slush and burn
> it. Then they see how many degrees the water is. I think. Ask in
> rec.food.cooking, there may (I don't know it's been a while) be a fellow
> named Shankar there who's a food chemist.
>
> B/



Look up "bomb calorimeter" with your favorite search engine.

Best regards,
Bob

in article , Andy Petro at
wrote on 11/8/04 1:45 PM:

> Anyone know how the number of calories in the different kinds of food are
> measured . Is it chemical,heat or other .
> No one seems to be able to tell me.
>
>
used to be burned in a bomb calorimeter.
Ellen
--

ellen wickberg wrote:

> in article , Andy Petro at
> wrote on 11/8/04 1:45 PM:
>
>>Anyone know how the number of calories in the different kinds of food are
>>measured . Is it chemical,heat or other.
>>No one seems to be able to tell me.
>>
> used to be burned in a bomb calorimeter.

Sorta. They measure actual caloric content of fats and proteins but
estimate carb counts. It called "by exception" and means that anything
not a fat or protein is automatically designated a carb whether we can
digest it or not. So the calorimeter measures total energy, some of
much of which isn't available to us. Cellulose is technically a carb,
but we don't digest it. Likewise pectin. In full-scale descriptions,
they'll generally be listed as fiber under carbs, but the calories
they contain will be included in the total. There are some fibers that
we digest partially, and that clouds the issue a bit further. Sugar
alcohols are like that. They're fewer calories than other sweeteners,
but they still carry some. Just to make that one more complex,
different people digest them to varying degrees. Caloric info on food
labels are approximations.

BTW, alcohol is another macro nutrient at 7 cals/gm that isn't often
listed on labels.

I think the USDA nutrient database explains all that, IIRC.

Pastorio

ellen wickberg wrote:

> in article , Andy Petro at
> wrote on 11/8/04 1:45 PM:
>
>>Anyone know how the number of calories in the different kinds of food are
>>measured . Is it chemical,heat or other.
>>No one seems to be able to tell me.
>>
> used to be burned in a bomb calorimeter.

Sorta. They measure actual caloric content of fats and proteins but
estimate carb counts. It called "by exception" and means that anything
not a fat or protein is automatically designated a carb whether we can
digest it or not. So the calorimeter measures total energy, some of
much of which isn't available to us. Cellulose is technically a carb,
but we don't digest it. Likewise pectin. In full-scale descriptions,
they'll generally be listed as fiber under carbs, but the calories
they contain will be included in the total. There are some fibers that
we digest partially, and that clouds the issue a bit further. Sugar
alcohols are like that. They're fewer calories than other sweeteners,
but they still carry some. Just to make that one more complex,
different people digest them to varying degrees. Caloric info on food
labels are approximations.

BTW, alcohol is another macro nutrient at 7 cals/gm that isn't often
listed on labels.

I think the USDA nutrient database explains all that, IIRC.

Pastorio