Carbohydrates, also known as carbs, refer to starches (complex carbohydrates) and to sugars (simple carbohydrates).
The Role of Carbohydrates in the Human Diet
Strictly speaking, carbohydrates are not necessary for human nutrition because proteins can be converted to glucose, which the body uses for energy. The traditional diet of many peoples consists of nearly no carbohydrates, and these people have been shown to be perfectly healthy. However, carbohydrates require less water to digest than do proteins or fats.
Problems have been cited for the long term effects of a no-carbohydrate diet. These include reduced athletic performance, possible brain damage, and nephrotoxicity. The brain can only utilize carbohydrates for energy, and protein may not supply enough in many cases. The increase in protein means that more ammonia groups need to be removed from the blood.
Carbohydrates have a varying degrees of glycemic index. People with diabetes or hyperglycemia (elevated blood glucose levels) need to carefully monitor their carbohydrate intake to prevent complications related to prolonged high blood glucose levels or acute hypoglycemia (too little blood glucose), and avoiding foods with high glycemic indexes can help.
Cooking with Carbohydrates
The dry heat of baking changes the structures of starches, partially sealing in the food's moisture. Browning can occur by caramelization of sugars and the Maillard reaction.
The most common baked item is bread. Variations in the ovens, ingredients and recipes used in the baking of bread result in the wide variety of breads produced around the world. Over time breads become hard in a process known as going stale. This is not primarily due to moisture being lost from the baked products, but more a reorganization of the way in which the water and starch are associated over time. This process is similar to recrystallization, and is promoted by storage at cool temperatures, such as those of a domestic refrigerator.