A recent study published in the American Journal of Clinical Nutrition1 investigated the effects of video games on energy balance in 120 young adults. The aim of the experiment was to discover if motion-controlled video games increase energy expenditure and thus might be beneficial in weight loss when compared to sedentary video games or television watching. The authors reported that those subjects participating in video games which required a degree of physical input had higher calorie intakes than those undergoing sedentary activity which included conventional video games and television watching. The calorie intake was measured from snacks provided during the 1 hour test session. However, they also reported that the energy expenditure was higher in the motion-controlled video games subjects, which resulted in a lower energy surplus compared to the television and sedentary video game groups.
The surplus for motion controlled video games, sedentary video games and television watching was 376, 533 and 638 kcal, respectively. Therefore even the video games that required physical movement for control still caused an energy surplus over the one hour test period if food is available for consumption simultaneously. This highlights the energy efficiency of exercise and supports other data to show that exercise causes only minimal calorie expenditure. Over a 24 hour period the resting metabolic rate (RMR) accounts for the vast majority of energy expended. The RMR is in turn related to the amount of muscle mass a subject possesses. Physical activity, even if performed at a high intensity does not produce a large increase in total energy expenditure when compared to the increase in RMR experienced from an increase in muscle mass.
From these study results the authors concluded that video games that require physical activity to control the movement may be beneficial compared to sedentary modes of recreation. However, there are a number of problems with this type of study that are not immediately obvious from the data, and care needs to be taken to analyse the bigger picture when investigating such findings. The main problem with such studies is they are far too short-term to learn anything about obesity. Energy balance is highly complex and requires longer study times for firm conclusions to be drawn. For example, other studies have shown that increasing physical activity does not cause increased energy expenditure. This is because the increased expenditure of the physical activity is balanced by other periods of lower energy expenditure, such as rest.
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