Researchers claim to have found that an energy drink containing sugar, added caffeine and guarana causes the body to convert sugar into fat more rapidly than drinks such as lemonade. Lemonade and other sodas are already being blamed by consumer groups for their role in increasing childhood obesity as many have a high sugar content.
For the latest study researchers recruited 10 healthy women aged 18 to 22 from a range of ethnicities. The subjects fasted overnight and were randomly given either 250ml of an energy drink containing 28g sucrose and 81mg caffeine per 250ml can, which is similar to the amount of sugar in soft drinks and caffeine in a brewed cup of coffee or lemonade on the first day and the alternative on the second day of testing. Lemonade contains around the same amount of sugar as energy drinks and is also carbonated but it contains no caffeine unlike cola drinks. The sugar in both drinks was absorbed rapidly into the bloodstream - within a minute, however researchers say that when caffeine is also present the sugar is more quickly converted to fat.
Coffee's impact on sugar metabolism is currently unclear but the beverage has been linked to a reduced risk of diabetes but it is not yet known whether this is down to the caffeine content or other compounds in coffee.
Thus researchers conclude saying that the study is limited by its small sample size and the fact that the subjects were all young women. Hence they call for further research, to look into the long term effects of combined caffeine and sugar on sedentary people's health.