Objective:Despite extensive research on framing effects in public health communication, there is still a lack of knowledge on how gain frames v. loss frames can encourage healthy eating behaviour among children.Design:Drawing on the Prospect Theory as well as on the Reactivity of Embedded Food Cues in Advertising Model, an experiment exposed children to an audio-visual cartoon movie with gain-framed nutritional messages about eating fruit (gain condition), loss-framed nutritional messages about eating fruit (loss condition) or a message without any food (control group). Children’s fruit intake was measured as the dependent variable. Children’s awareness of gain- and loss-framed arguments was treated as mediators, while children’s age and parents’ self-reported food-related mediation styles were modelled as moderators.Setting:Vienna, Austria, in 2018.Participants:Children aged 6–10 years (N 161).Results:Children in the gain frame group were more aware of gain-framed arguments, and children in the loss frame group were more aware of loss-framed arguments than those in the control group. However, only the mediator awareness of gain-framed arguments increased fruit intake. Additionally, there was a direct effect of the gain-framed message on fruit intake compared to the control group. The loss condition did not reveal such an effect. Neither parent’s food-related mediation styles nor children’s age moderated those results.Conclusion:Gain-framing seems to be more effective in influencing children’s healthy food choices compared to loss-framing. Implications for health communication strategies aimed at children are discussed.