Effectiveness of the Lunch is in the Bag program on communication between the parent, child and child-care provider around fruits, vegetables and whole grain foods: A group-randomized controlled trial

•Data on parent communication with their preschooler and childcare providers around nutrition is sparse.•We evaluated intervention effects on parent–child and parent-childcare provider around fruits, vegetables and whole grains.•Communication between parent–child and parent-childcare provider was low at baseline.•Results showed significant improvements in parent communication with childcare provider around fruits and vegetables.