noncarbohydrate

Noncarbohydrate is a general term used to describe any chemical compound that is not a carbohydrate. In chemistry, carbohydrates are a broad class of organic molecules that include monosaccharides (such as glucose and fructose), disaccharides (such as sucrose and lactose), oligosaccharides, and polysaccharides (such as starch and cellulose). They are typically composed of carbon, hydrogen, and oxygen in a characteristic ratio and often expressed by the empirical formula (CH2O)n. Noncarbohydrates therefore encompass lipids, proteins, nucleic acids, vitamins, minerals, alkaloids, and many other organic and inorganic substances. The term is used mainly as a convenience in discussions of composition, metabolism, or labeling, rather than as a formal taxonomic category.

In nutrition and food science, noncarbohydrate can refer to the portion of a food’s mass that is not carbohydrate. Nutrition labeling often reports carbohydrate separately, so the noncarbohydrate fraction includes protein, fat, moisture, minerals, and vitamins. In proximate analysis, carbohydrate content is sometimes calculated by difference: Carbohydrates = 100% − (protein + fat + ash + moisture). Thus the noncarbohydrate portion comprises protein, fat, ash, and moisture. It is important to note that fats and proteins are not carbohydrates, but are energy-yielding macronutrients; carbohydrates themselves include starches and sugars among others.

Terminology usage varies by field and jurisdiction. Some discussions use noncarbohydrate to contrast with carbohydrate-rich dietary components, while others reserve it for analytical distinctions in food science. As a result, the exact meaning should be inferred from context.