A startling study conducted by AUT Professor of Nutrition Elaine Rush states that consumption of energy drinks which contain high amounts of sugar as well as caffeine contributes to obesity.
The study found that an energy drink containing sugar, added caffeine and guarana (which also contains caffeine) causes the body to convert sugar into fat more rapidly than lemonade. "These results could have huge implications when you think about how much sugar and caffeine people consume these days, and the high rates of inactivity," she says.
The team comprised Professor Rush as the leader and included AUT researcher Dr Vladimir Obolonkin and student Stephanie Schulz, Professor David Simmons from Auckland University's Waikato Clinical School and Dr Lindsay Plank of Auckland University's Department of Surgery.
They 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 or lemonade on the first day and the alternative on the second day of testing. Lemonade was chosen because while both drinks contain the same amount of sugar and are carbonated, it doesn't contain caffeine.
"When the women drank the energy drink or lemonade, the sugar was absorbed into their systems within a minute, giving them an immediate sugar rush".
"Sugar is a simple carbohydrate and evidence from this study shows that, coupled with a large amount of caffeine, the body rapidly turns it into stored fat."
The energy drink contains 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.
"These drinks are often marketed as energy-boosters and may be perceived as helpful for weight loss. This is misleading - they are a calorie-booster and may actually cause weight gain." Professor Rush recognises the study's limitations with its small sample size and the fact the subjects were all young women, but says its results are important as this area has not been explored before.
"There has been a great deal of research about sugar and obesity, but not the synergy between drinks and fat stores. This study also raises questions about the effects of consuming high-sugar foods and highly caffeinated drinks together in a short period of time." "This area needs further research, as well as the long term effects of combined caffeine and sugar on sedentary people's health," says Professor Rush.
Source: Asia Pacific Journal of Clinical Nutrition.