Abstract Background This abstract discusses the food environment intervention in Generation Healthy Kids (GHK). Promoting healthy food environments is a central aspect of public health efforts to prevent obesity, and supermarkets play a central role in shaping purchasing behaviors. As part of GHK we designed, implemented, and evaluated an intervention to promote sales of fruit and vegetables in supermarkets close to GHK schools. Methods Four supermarkets from a large supermarket chain agreed to participate. As controls, we selected four stores from the same chain in municipalities with similar socioeconomic profiles. The intervention was co-designed with store owners and the national chain. For nine weeks during 2024, intervention stores agreed to implement initiatives to increase sales of fruits and vegetables, including more prominent placement, ensuring high availability and quality, local offers, and promotion initiatives. Simultaneously, children's activities focusing on fruits and vegetables were organized in the store, e.g. taste testing and treasure hunts. We evaluated the intervention's effect on shelf space and sales of fruit and vegetables and assessed barriers for implementation through interviews with intervention store owners. Results Preliminary analyses indicate that the intervention did not affect amount of shelf space with fruit and vegetables (increase 1.5% vs. 6.5% in intervention vs control). Sales of fruit and vegetables increased in 2 intervention stores (index: 118-125), was stable in 1 store (index: 103) and decreased in 1 store (index: 87) compared with the same period the prior year. Comparison with control stores will be presented. Implementation barriers expressed by store owners were chain rules, a competitive market and lack of time. Perspectives Our findings support a need for national legislation regarding product placement and pricing, rather than local initiatives, to facilitate substantial changes in supermarket food environments.