08 July, 2011
Carbohydrates in an Egg White
Egg whites are a rich source of protein, vitamins and minerals. Although egg whites are composed almost entirely of water and protein, they also contain a trace of carbohydrates and fat. Carbohydrates should comprise a greater percentage of your diet than any other substance, so the amount of carbohydrates in an egg white provides a fairly insignificant source of this macronutrient.
The egg white from one large egg, weighing 33 g, contains 0.24 g of carbohydrates. Carbohydrates should account for 45 to 65 percent of your total caloric intake, and a 2,500-calorie diet calls for about 344 g of carbohydrates each day. The 0.24 g of carbohydrates in an egg white provides much less than 1 percent of the typical adult's minimum daily carbohydrate needs.
Almost all of the carbohydrates in an egg white exist in the form of sugars. Sugars are simple carbohydrates composed of either one or two saccharide molecules. Simple sugars form the building blocks for more complex carbohydrates, but, in their basic form, are broken down quickly and converted to glucose to provide cellular energy. An egg white contains 0.23 g of total sugars.
Most of the sugar -- 0.11 g -- in an egg white consists of the monosaccharide glucose. Monosaccharides are carbohydrates that contain just one saccharide molecule. Glucose exists naturally in the bloodstream, as well as dietary sources. After digestion, carbohydrates are converted to glucose and either used for immediate energy, stored in the muscles and liver in the form of glycogen for later energy use, converted to fat or used to synthesize non-essential amino acids. Egg whites also contain the monosaccharides fructose, lactose and galactose.
Disaccharides are carbohydrates that contain two monosaccharides joined together. An egg white contains 0.2 g each of the disaccharides lactose, maltose and sucrose. Lactose is formed from glucose and galactose, and is most commonly found in milk products. Maltose is formed from two glucose molecules, and is most commonly found in beer and cereals. Sucrose is a combination of glucose and fructose. Sucrose is in almost all foods containing carbohydrates, including table sugar, syrups, beet and cane sugar and honey.
- USDA National Nutrient Database for Standard Reference: Egg, White, Raw, Fresh
- Incredible Edible Eggs: Nutrient Chart
- "Essentials of Exercise Physiology"; William D. McArdle; 2006
- Institute of Medicine; Dietary Reference Intakes; Macronutrients; 2005
- vinicef/iStock/Getty Images