Sucralose is an artificial sweetener and sugar substitute. The majority of ingested sucralose is not broken down by the body, so it is noncaloric. In the European Union, it is also known under the E number E955. It is produced by chlorination of sucrose, selectively replacing three of the hydroxy groups to give a 1,6-dichloro-1,6-dideoxyfructose–4-chloro-4-deoxygalactose disaccharide. Sucralose is about 320 to 1,000 times sweeter than sucrose, three times as sweet as both aspartame and acesulfame potassium, and twice as sweet as sodium saccharin. Evidence of benefit is lacking for long-term weight loss with some data supporting weight gain and heart disease risks.