A serving size is a tool used by the United States Department of Agriculture (USDA) to measure amounts of food. On the nutrition labels stamped on most foods sold in stores, the serving size shows the nutritional information for the food. It will usually be a portion of the food labeled, and for that portion the amounts of vitamins, minerals, fats, and other things are indicated on the label. These labels are intended for comparing the nutritional information of different but similar foods. The nutrition facts represented per serving size include things like fat, sugar, calories, vitamins, protein, carbohydrates, and a number of other products of the food.
The serving size found on these labels represents the amount of food that one would normally eat in one sitting. This information is determined from nationwide surveys across the United States, and serving sizes are given in one of various ways. The methods of measurement include: cups and tablespoons for granular items; fractions for sliced items like pie or cake; numbers for grouped items like cherries or grapes; and grams for other grouped items, such as cereal.
Serving sizes tend to be generally smaller than most Americans will eat at one meal or one sitting, as many Americans tend to be unhealthy or at least slightly overweight. Examples include one cup of pasta; one cup of dry cereal; one hand-sized cut of steak; one half cup of milk; one fourth of a chicken breast; five cherry tomatoes; five sticks of celery; one half of an apple; or one half of a banana.
On the Food Pyramid, a serving size represents a daily nutrition recommendation for a healthy diet. The pyramid includes one serving of each type of food necessary in a day-to-day diet, including fruits, vegetables, meats, grains, sugars, oil, dairy, and another group including poultry, fish, dry beans, eggs, and nuts. These guidelines are determined, according to the USDA, by the considering of normal portion sizes from food consumption surveys; conveniences in relation to normal measuring sizes; nutrient content; and sizes from previous guides.