A reference to substances that a person takes into the body as food and the way they influence one's health: When buying his groceries at the local store, Jack read the labels; especially, those concerning the nutritional information of the products because he didn’t want to buy anything with too much sugar content.

A condition that can be caused by deficiency, an excess of one or more ingredients, or by a toxin or poisonous element in the diet:

• An intake of food that is deficient in carbohydrates is usually deficient in proteins, too.
• An excess substances can cause obesity and dental caries which are the most common disorders in the U.S.
• Toxic effects are disorders that can arise from the presence of poisonous substances in the food which may be caused by industrial pesticides, fertilizers, pollutants, and other chemicals which can also contaminate food.

Relating to a measure of the amount of energy and the maintenance of life that become available to the body from a given edible product after ingestion: There are ranking systems, developed by governments or nonprofit organizations, pertaining to the nutritional value of foods in order to inform the customers about the vitamins, minerals, dietary fiber, Omega-3 fatty acids, added sugar, etc. in foods.