This document discusses carbohydrate nutrition. It defines nutrition and lists the major nutrients, including carbohydrates. Carbohydrates are broken down into sugars (mono- and di-saccharides) and non-sugars (oligo- and polysaccharides). Examples of mono-, di-, and polysaccharides are provided along with their structures and metabolic pathways. The document also discusses how plants and animals derive energy from carbohydrate metabolism through processes like glycolysis, the Krebs cycle, and the electron transport chain.