How do they figure out how many calories are in something?

[Elliot0409]

How do they figure out how many calories are in something?

[fittchica]

I think they do like this:
1gram of carbohydrates=4 calories
1gram of Protein=4 cals
1 gram of fat=9
It is done by weight. So by calculating the grams and type of food(p/f or carbs) it can be figured out...

[Elliot0409]

Ok..then my question is:

how do they figure out carbs, fat, protein etc..etc..???

[in10city]

How do they figure out how many calories are in something?

Good lord... is this thread #1,000? All of this spoon feeding is making me lose faith in mankind ...

http://www.cfsan.fda.gov/~lrd/CFR101-9.HTML
(1) ``Calories, total,'' ``Total calories,'' or ``Calories'': A
statement of the caloric content per serving, expressed to the nearest
5-calorie increment up to and including 50 calories, and 10-calorie
increment above 50 calories, except that amounts less than 5 calories
may be expressed as zero. Energy content per serving may also be
expressed in kilojoule units, added in parentheses immediately following
the statement of the caloric content.
(i) Caloric content may be calculated by the following methods.
Where either specific or general food factors are used, the factors
shall be applied to the actual amount (i.e., before rounding) of food
components (e.g., fat, carbohydrate, protein, or ingredients with
specific food factors) present per serving.
(A) Using specific Atwater factors (i. e., the Atwater method) given
in Table 13, ``Energy Value of Foods--Basis and Derivation,'' by A. L.
Merrill and B. K. Watt, United States Department of Agriculture (USDA)
Handbook No. 74 (slightly revised, 1973), which is incorporated by
reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51 and is
available from the Office of Nutritional Products, Labeling and Dietary
Supplements (HFS-800), Center for Food Safety and Applied Nutrition,
Food and Drug Administration, 5100 Paint Branch Pkwy., College Park, MD
20740, or may be inspected at the Office of the Federal Register, 800
North Capitol St. NW., suite 700, Washington, DC.;
(B) Using the general factors of 4, 4, and 9 calories per gram for
protein, total carbohydrate, and total fat, respectively, as described
in USDA Handbook No. 74 (slightly revised 1973) pp. 9-11, which is
incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR
part 51 (the availability of this incorporation by reference is given in
paragraph (c)(1)(i)(A) of this section);

[[Page 25]]

(C) Using the general factors of 4, 4, and 9 calories per gram for
protein, total carbohydrate less the amount of insoluble dietary fiber,
and total fat, respectively, as described in USDA Handbook No. 74
(slightly revised 1973) pp. 9-11, which is incorporated by reference in
accordance with 5 U.S.C. 552(a) and 1 CFR part 51 (the availability of
this incorporation by reference is given in paragraph (c)(1)(i)(A) of
this section;
(D) Using data for specific food factors for particular foods or
ingredients approved by the Food and Drug Administration (FDA) and
provided in parts 172 or 184 of this chapter, or by other means, as
appropriate; or
(E) Using bomb calorimetry data subtracting 1.25 calories per gram
protein to correct for incomplete digestibility, as described in USDA
Handbook No. 74 (slightly revised 1973) p. 10, which is incorporated by
reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51 (the
availability of this incorporation by reference is given in paragraph
(c)(1)(i)(A) of this section).

...

(6) ``Carbohydrate, total'' or ``Total carbohydrate'': A statement
of the number of grams of total carbohydrate in a serving expressed to
the nearest gram, except that if a serving contains less than 1 gram,
the statement ``Contains less than 1 gram'' or ``less than 1 gram'' may
be used as an alternative, or if the serving contains less than 0.5
gram, the content may be expressed as zero. Total carbohydrate content
shall be calculated by subtraction of the sum of the crude protein,
total fat, moisture, and ash from the total weight of the food. This
calculation method is described in A. L. Merrill and B. K. Watt,
``Energy Value of Foods--Basis and Derivation,'' USDA Handbook 74
(slightly revised 1973) pp. 2 and 3, which is incorporated by reference
in accordance with 5 U.S.C. 552(a) and 1 CFR part 51 (the availability
of this incorporation by reference is given in paragraph (c)(1)(i)(A) of
this section).
(i) ``Dietary fiber'': A statement of the number of grams of total
dietary fiber in a serving, indented and expressed to the nearest gram,
except that if a serving contains less than 1 gram, declaration of
dietary fiber is not required or, alternatively, the statement
``Contains less than 1 gram'' or ``less than 1 gram'' may be used, and
if the serving contains less than 0.5 gram, the content may be expressed
as zero. Except as provided for in paragraph (f) of this section, if
dietary fiber content is not required and as a result, not declared, the
statement ``Not a significant source of dietary fiber'' shall be placed
at the bottom of the table of nutrient values in the same type size.
(A) ``Soluble fiber'' (VOLUNTARY): A statement of the number of
grams of soluble dietary fiber in a serving may be declared voluntarily
except when a claim is made on the label or in labeling about soluble fiber, label
declaration shall be required. Soluble fiber content shall be indented
under dietary fiber and expressed to the nearest gram, except that if a
serving contains less than 1 gram, the statement ``Contains less than 1
gram'' or ``less than 1 gram'' may be used as an alternative, and if the
serving contains less than 0.5 gram, the content may be expressed as
zero.
(B) ``Insoluble fiber'' (VOLUNTARY): A statement of the number of
grams of insoluble dietary fiber in a serving may be declared
voluntarily except that when a claim is made on the label or in labeling
about insoluble fiber, label declaration shall be required. Insoluble
fiber content shall be indented under dietary fiber and expressed to the
nearest gram except that if a serving contains less than 1 gram, the
statement ``Contains less than 1 gram'' or ``less than 1 gram'' may be
used as an alternative, and if the serving contains less than 0.5 gram,
the content may be expressed as zero.
(ii) ``Sugars'': A statement of the number of grams of sugars in a
serving, except that label declaration of sugars content is not required
for products that contain less than 1 gram of sugars in a serving if no
claims are made about sweeteners, sugars, or sugar alcohol content.
Except as provided for in paragraph (f) of this section, if a statement
of the sugars content is not required and, as a result, not declared,
the statement ``Not a significant source of sugars'' shall be placed at
the bottom of the table of nutrient values in the same type size. Sugars
shall be defined as the sum of all free mono- and disaccharides (such as
glucose, fructose, lactose, and sucrose). Sugars content shall be
indented and expressed to the nearest gram, except that if a serving
contains less than 1 gram, the statement ``Contains less then 1 gram''
or ``less than 1 gram'' may be used as an alternative, and if the
serving contains less than 0.5 gram, the content may be expressed as
zero.
(iii) ``Sugar alcohol'' (VOLUNTARY): A statement of the number of
grams of sugar alcohols in a serving may be declared voluntarily on the
label, except that when a claim is made on the label or in labeling
about sugar alcohol or sugars when sugar alcohols are present in the
food, sugar alcohol content shall be declared. For nutrition labeling
purposes, sugar alcohols are defined as the sum of saccharide
derivatives in which a hydroxyl group replaces a ketone or aldehyde
group and whose use in the food is listed by FDA (e.g., mannitol or
xylitol) or is generally recognized as safe (e.g., sorbitol). In lieu of
the term ``sugar alcohol,'' the name of the specific sugar alcohol
(e.g., ``xylitol'') present in the food may be used in the nutrition
label provided that only one sugar alcohol is present in the food. Sugar
alcohol content shall be indented and expressed to the nearest gram,
except that if a serving contains less than 1 gram, the statement
``Contains less then 1 gram'' or ``less than 1 gram'' may be used as an
alternative, and if the serving contains less than 0.5 gram, the content
may be expressed as zero.
(iv) ``Other carbohydrate'' (VOLUNTARY): A statement of the number
of grams of other carbohydrates may be declared voluntarily. Other
carbohydrates shall be defined as the difference between total
carbohydrate and the sum of dietary fiber, sugars, and sugar alcohol,
except that if sugar alcohol is not declared (even if present), it shall
be defined as the difference between total carbohydrate and the sum of
dietary fiber and sugars. Other carbohydrate content shall be indented
and expressed to the nearest gram, except that if a serving contains
less than 1 gram, the statement ``Contains less than 1 gram'' or ``less
than 1 gram'' may be used as an alternative, and if the serving contains
less than 0.5 gram, the content may be expressed as zero.

[in10city]

Ok..then my question is:

how do they figure out carbs, fat, protein etc..etc..???

Read the labels or look food up on http://www.nutritiondata.com