Deakin health researchers have found that 10.3 per cent of the sucrose in sugar sweetened drinks, such as colas and energy drinks, can be taken out without causing a noticeable flavour difference if the caffeine is also removed. This reduction in sugar equates to 116 less kilojoules per 500 ml serving.
“The results of this study show that a significant amount of energy in sugar sweetened drinks can easily be reduced by simply removing the caffeine,” said Associate Professor Russell Keast, the lead researcher on the project.
“More than 80 per cent of the population will not notice a taste difference if the caffeine is removed along with just over 10 per cent of the sugar.
“Reducing the energy content of sugar sweetened drinks could help reduce the growing rate of overweight and obesity being experienced in Australia and around the world.”
Caffeine is a widely consumed, mildly addictive chemical that occurs naturally in coffee, tea and chocolate, but is an additive to soft drinks—mostly cola-flavoured drinks and energy drinks.
For the study, a team of specially selected taste testers were asked to detect the presence of caffeine in water, a sucrose (sugary tasting) solution and soft drink. They also assessed the amount of sucrose that could be removed from a caffeinated and a non-caffeinated sugary soft drink before the flavour was affected.
“What we ultimately found was that the caffeine in soft drinks influenced the sweetness meaning we could decrease the amount of sugar added to the soft drink without affecting the flavour,” Dr Keast said.
“Using a caffeinated soft drink as a control, we found that when we removed caffeine, we could also remove 10 per cent of the sugar before a perceivable difference in the flavour was detected by more than 80 per cent of the tasters.
“This shows that caffeine bluntens our perception of sweetness, a reason why a large number of people add sugar to their tea or coffee to get the desired flavour.”
In the study, the researchers also estimated the ‘caffeine-calorie’ effect of reducing the energy in soft drinks on weight gain in adults and children across their lifetime.
“If the caffeine and 10.3 per cent of the sugar was removed from soft drinks, we estimate an energy intake reduction of 56 kilojoules per day for adults and 61.4 kilojoules a day in children. These calculations are based on the estimated soft drink consumption in the United States,” explained Dr Lynn Riddell, a co-researcher on the study.
“These small changes in energy intake can become very significant when we consider average soft drink consumption is very high. In fact, this caffeine-calorie effect accounts for 600 gram weight increase for adults and 142 gram weight increase in children, which equate to two years of average weight gain for adults and 1.1 years for children.”
The study—The influence of caffeine on energy content of sugar-sweetened beverages ‘The Caffeine-Calorie Effect’—is published online in the European Journal of Clinical Nutrition.