Are energy drinks contributing to the obesity epidemic?

The consumption of energy drinks containing sucrose and caffeine is increasing worldwide. Ten healthy women aged 18 to 22 years and fasted overnight were randomly allocated to a standardised dose of sucrose either as an "energy " drink (containing sucrose and caffeine) or lemonade on the first day and then crossed over to the alternative drink on a second day. For thirty minutes before and thirty minutes after drinking oxygen consumption and carbon dioxide production were measured in the resting subject breath-by-breath by indirect calorimetry and the rates of carbohydrate and fat oxidation calculated. Energy drink consumption apparently caused increased carbohydrate oxidation (P = 0.004) and reduced lipid oxidation (P = 0.004) compared to lemonade. The longer term effects of combined caffeine and sucrose intake, particularly in sedentary individuals, on metabolism and body fatness needs further examination.