Research has shown that playing electronic games and watching television can cause weight gain and are associated with obesity. For example, subjects playing an electronic game while eating have been shown to consume more energy when compared to those given no distraction (here). Other studies have shown that some individuals are susceptible to adverts on television and this causes increases in subsequent food intake (here). These example highlight the fact that the sedentary behaviour inherent in watching television and playing electronic games may not be the only reason they are associated with weight gain, and other more complex mechanisms may be involved. Because electronic game playing is a relatively new phenomenon, research investigating the effects on energy balance has only been reported recently. Playing electronic games is growing in popularity amongst children and this is problematic because rates of childhood obesity are increasing in some Western nations.
The mechanisms by which game playing might cause weight gain are not fully understood, but may go beyond the notion of sedentary behaviour causing decreased energy expenditure. In fact, research suggests that electronic game playing is associated with an increased energy intake. For example, researchers1 have examined the acute effects of 1 hour of sedentary electronic game playing on various components of energy balance. The results showed that heart rate, systolic blood pressure, diastolic blood pressure, sympathetic tone and mental workload were all higher during the period of game playing compared to rest. Interestingly, energy expenditure increased during game playing and was 21.3kcal higher than at rest. However, in a subsequent ad libitum lunch energy intake was 80.1kcal higher when compared to energy intake following rest. A total energy surplus of 150.1kcal was consumed when playing 1 hour of electronic games per day, compared to resting.
These results suggest that 1 hour of playing electronic games a day may increase the risk of obesity not by decreasing energy expenditure, but by actually increasing energy intake. Although increased energy was consumed following electronic game playing, there was no increase in hunger and there was no subsequent compensation for this energy throughout the rest of the day. Monitoring of hormonal levels during the playing of the games did not reveal any changes to insulin, glucose or ghrelin levels that would suggest up-regulation of appetite. The authors suggested that mental stress might be the cause of the increased food intake, with electronic game playing producing a particular type of mental workload that is biologically demanding for the body. The additional component of mental workload might therefore be needed to be taken into consideration during assessment of sedentary behaviour.
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