Background: A cluster-randomized trial at 30 early care and education centers (Intervention = 15, waitlist Control = 15) showed the Lunch Is in the Bag intervention increased parents' packing of fruits, vegetables, and whole grains in their preschool children's bag lunches (parent-child dyads = 351 Intervention, 282 Control). Purpose: To examine the utility of structuring the trial's process evaluation to forecast use, sustainability, and readiness of the intervention for wider dissemination and implementation. (author abstract)