Supporting family meal frequency: Screening Phase results from the Simply Dinner Study.

We aimed to test main, additive, interactive effects, and feasibility of all possible combinations of six intervention components implemented for 8 weeks (Cooking/Serving Resources; Meal Delivery; Ingredient Delivery; Community Kitchen; Nutrition Education; Cooking Demonstrations). Primary outcomes were family meal frequency and preschoolers' dietary quality; secondary outcomes included family meal preparation type, meal preparation barriers, family functioning, and kitchen inventory adequacy. All possible intervention combinations were tested using a randomized factorial trial design in the first phase of a Multiphase Optimization Strategy (MOST). Feasibility was assessed via attendance, delivery logs, and satisfaction. Parent-reported data collection included: socio-demographics, frequency and type of family meals; preschooler dietary intake; perceived barriers to meal planning and preparation; assessment of family functioning; and a kitchen inventory of materials generally needed for meal preparation. Participants (n = 499) were recruited at two Head Start agencies in mid-Michigan with data collection and delivery of some intervention components in participants' homes. Promising intervention bundles were identified by evaluating pre-to post-intervention effect sizes. The combination of Cooking/Serving Resources and Meal Delivery increased family meal frequency (Cohen's d = 0.17), cooking dinner from scratch (d = 0.21), prioritization of family meals (d = 0.23), and kitchen inventory (d = 0.46) and decreased use/consumption of ready-made (d = -0.18) and fast foods (d = -0.23). Effects on diet quality were in the expected direction but effect sizes were negligible. Community Kitchen, Nutrition Education, and Cooking Demonstration showed poor feasibility due to low attendance while Ingredient Delivery was infeasible due to staffing challenges related to its labor intensity. Additionally, although not one of our pre-specified outcomes, Cooking/Serving Resources (RR = 0.74) and Meal Delivery (RR = 0.73) each decreased food insecurity. Cooking/Serving Resources combined with Meal Delivery showed promise as a strategy for increasing family meal frequency.