Acute effects of ingesting a commercial thermogenic drink on changes in energy expenditure and markers of lipolysis

BACKGROUND To determine the acute effects of ingesting a thermogenic drink (Celsius, Delray Beach, FL) (TD) on changes in metabolism and lipolysis. METHODS Healthy college-aged male (23.2 +/- 4.0 y, 177.2 +/- 6.1 cm, 81.7 +/- 11.3 kg, 22.8 +/- 7.3 % fat; n = 30) and female (23.4 +/- 3.1 y, 165.6 +/- 8.7 cm, 62.1 +/- 9.9 kg, 28.3 +/- 7.4 % fat; n = 30) participants were matched according to height and weight to consume 336 ml of the TD or a non-caloric, non-caffeinated placebo (PLA). After a 12 h fast, participants reported for pre-consumption measures of height, weight, heart rate, blood pressure, resting energy expenditure (REE), respiratory exchange ratio (RER), glycerol and free-fatty acid (FFA) concentrations. REE and RER were determined at 60, 120, and 180 min post-consumption. Serum glycerol and FFA concentrations were determined at 30, 60, 120 and 180 min post-consumption. RESULTS When compared to PLA, TD significantly increased REE at 60, 120 and 180 min (p < 0.05). FFA concentrations were significantly greater in TD compared to PLA at 30, 60, 120 and 180 min post-consumption (p < 0.05). No between-group differences were found in RER. CONCLUSION Acute TD ingestion significantly increased REE, FFA and glycerol appearance. If sustained, these changes may help to promote weight loss and improve body composition; however, these findings are currently unknown as are the general safety and efficacy of prolonged consumption.