Emerging adults (EAs), defined as adults aged 18 to 25, remain a difficult group to engage in healthy behaviours (including positive dieting and eating patterns). The environmental elements that influence the health behaviours of EAs have been studied. However, the literature is mixed on how online game environments, including eSports and game streaming, can be used to positively engage EAs. In this scoping review, we identified and analysed research on online games, EAs, and dietary patterns to create a behavioural ecological map of influences that intersect with EAs through online games. In total, 75 studies were found, identifying 23 influences that intersect with EAs through their online game use. ESports organisations, eSports athletes, and content creators may be areas of future research (and intervention) as these factors could positively influence the dietary behaviours of EAs (through online games).