### Question
How is the term serving* or *serving size defined?


### Answer
The term **serving* or *serving size** is defined in *21 CFR § 101.9* as the following:

> an amount of food customarily consumed per eating occasion by persons 4 years of age or older which is expressed in a common household measure that is appropriate to the food. 

#### Citation:
  - *21 CFR § 101.9*
