E J Hart’s research while affiliated with Franciscan Hospital for Children and other places

... For instance, Stone & Gentile (2008) found that the effects of the amount of game play are mostly related to activity displacement (i.e., if more time is spent playing video games, there is less time for studying or exercising) rather than to collaborative learning. More time spent playing games is positively correlated with obesity (Subrahmanyam et al., 2000) or other health issues (Brasington, 1990). Players who are driven by achievement, for instance, may spend excessive amount of time advancing their characters to the highest possible level, but as soon as an expansion pack is released, there is a newer and higher benchmark for that achievement that requires spending even more time in attaining these new goals. ...

Reference:

Employee Proactiveness to Engage in Sustainable Consumption Leading to Societal Benefits