 Diet Coke and Diet Pepsi have capitalized on the markets of people who require low sugar regimens, such as diabetics and people concerned with calorie intake.In the UK, a 330 ml can of Diet Coke contains around 1.3 kilocalories (5 kilojoules) compared to 142 kilocalories (595 kJ) for a regular can of Coca-Cola.Diet Coke was sweetened with aspartame, an artificial sweetener, after the sweetener became available in the United States in 1983.