Artificial sweeteners are made up from molecules that are not found in the natural environment. There are five alternative sweeteners that have been approved to be used in commercially processed foods: Aspartame, Acesulfame-K, Sucralose, Neotame, Cyclamates.
Aspartame is completely broken down by the body into its two component amino acids, phenylalanine and aspartic acid. Since aspartame is not stable at baking temperatures, its use is limited in baked foods. Aspartame has low caloric value and it does not lead to tooth decay. Aspartame can be used by the body just as any other protein. Phenylketonuria represents the rare genetic disorder that prevents metabolizing of phenylalanine, hence, since one of aspartame's components is phenylalanine, it is important to be avoided by the patients carrying this genetic disorder.
Acesulfame potassium is not metabolized by the body and it is similar to aspartame. The difference is that acesulfame potassium is more stable at higher temperatures.
Neotame represents a new sweetener and it has a molecular structure similar to aspartame, being composed of aspartic acid and phenylalanine. It has no calories and it is 40 times sweeter than aspartame.