Effects of Energy Drinks

This study is designed to test the efficacy of an energy drink compared to placebo via a double-blind, crossover, randomized clinical trial. Energy levels will be assessed before and after consumption of the test beverages on 2 days separated by a week in 200 participants aged 18-70 years. The study is crossover because the participants will be (randomly) receiving one drink on Test Day 1 and the other drink on Test Day 2.

After signing written informed consent, participants will be fed a light lunch, and their pulse, weight and height measured. A baseline battery of computer-based tests to assess energy levels will be conducted. These computer-based measures will take ~40 minutes to complete and will include: a) a long-term memory test b) a Profile of Mood States (POMS2) brief form; c) Rapid Visual Information Processing (RVIP) test, d) The N-Back Task; d) Reaction time online test; f) the Flanker Task. Participants will then be asked to fill out a baseline survey (30 min), with questions about current health-related behaviors, specifically questions about physical activity and diet.

Upon completing the baseline battery (survey administered at test session 1 only), participants will be randomly administered the energy drink or the placebo to consume while observed. Subsequently, the battery of computer-based tests to assess energy levels will be re-administered 30 minutes, 2.5 hours and 5 hours after consumption of the test drink.

The study intervention will be double-blinded: participants will be blinded to whether they are receiving the active or the placebo drink, and study team members will also not be aware of the assignment.

When the study ends, full compensation will be given if the intervention is fully completed; if the intervention is not fully completed, partial compensation will be given.

Inclusion criteria

• Fluent in reading English
• High school graduate as lowest education level

Exclusion criteria

• Non-smoker
• No diagnosed/treated cognitive/psychiatric conditions by self-report
• No diagnosed/treated diabetes, hypoglycemia or thyroid condition by self-report
• No current use of prescription stimulant medications by self-report
• No allergies or sensitivities to foods, ingredients or chemicals by self-report, that are contained in the test drink or placebo
• No diagnosed phenylketonuria