Metabolic Response to Playing Video Games

The study is investigating the metabolic response to playing competitive non-violent and competitive violent video games. The primary hypothesis is that the metabolic response in the violent game group will differ from the other two groups, due to activation of the stress response. The investigators are using an experimental approach, whereby 72 young men are randomised to one of three groups: watching television (TV), playing the non-violent video game 'FIFA2013', or playing the violent video game 'Call of Duty'. Participants arrive fasted, and are given a standardised breakfast. After measurements of weight, height and waist girth, they then are assigned to one of the three groups. Baseline blood pressure, heart rate and appetite/mood data are collected, along with a saliva sample for measurement of the 'stress' hormone, cortisol. The investigators will collect these data again at 4 time-points during the one hour game-playing session. At the end of the study, the allow the participants half an hour of rest, during which they can choose from a variety of sweet or savoury snacks. The investigators will compare the data from the three groups, to test whether changes in blood pressure, heart rate and salivary cortisol, as well as snack consumption, are greater in the group playing the violent game.