This article is from the Fat-free Diet FAQ, by artemis@rahul.net (Michelle Dick) with numerous contributions by others.
Often the caloric values and protein, fat, and carbohydrate amounts
listed on a food label don't "add up". The most common reason for
this is rounding. The NLEA specifies the following rounding rules
(all per serving):
FAT: Amounts between 0 and 0.5 grams can be expressed as 0. Amounts
between 0.5 and 5 grams can be rounded to the nearest 0.5 gram
increment. Amounts greater than 5 grams can be rounded to the
nearest gram.
PROTEIN AND CARBOHYDRATES: Amounts between 0 and 0.5 grams can be
expressed as 0. Amounts between 0.5 and 1 gram can be expressed as
"contains less than 1 gram". Amounts above 1 gram are rounded to the
nearest gram.
CALORIES FROM FAT: Amounts from 0 to 5 calories can be expressed as
0. Amounts between 5 and 50 can be rounded to the nearest 5
calories. Amounts above 50 calories can be rounded to the nearest
10 calories.
 
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