Effects of 'energy' drinks on mood and mental performance: critical methodology

Beneficial effects for mood and cognitive performance are believed to influence food and drink choice. The purpose of the present study was to demonstrate a sensitive methodology for providing objective evidence of such effects. A mildly fatiguing repetitive task formed the context for assessing the potential restorative effects of caffeine-containing 'energy' drinks. The methodology used was designed to account for a range of theorised variations in the data, many of which are often overlooked in current research. Significant effects of the energy drinks on task performance and self-rated mood were found. These effects can be summarised with the terms 'alerting, 'revitalising', 'awakening' and providing mental energy, and appear to be mainly caffeine related. (C) 2002 Elsevier Science Ltd. All rights reserved.