BackgroundMany researchers advocate for increased culinary skills education programs for youth in response to high rates of obesity and the typically unhealthy diets of American children (Nelson et al, 2013). Illinois Junior Chefs (IJC) is a statewide nutrition education program for children that provides hands‐on cooking education, aiming to change participants' dietary behaviors and attitudes. As a statewide program, implementation occurred in sites across Illinois with various constraints that influenced program structure.ObjectiveThis study examined the influence of several characteristics related to program structure on the outcomes of IJC. Specifically, we investigated whether program impact differed based on the timing of delivery (five consecutive days vs. once per week classes) and past participation in a cooking program, and whether student to teacher ratio and hours of programming were related to program outcomes.MethodIJC is a culinary education program that provides opportunities for students to learn hands‐on cooking skills. The program typically consists of five two‐hour lessons, but some sites varied in their adherence to this schedule. Each lesson has a food group theme (i.e., vegetables) paired with a recipe (i.e. vegetable lo mein) and a relevant cooking skill (i.e., knife skills).Participants (n = 1194, aged 6 – 18) were 59.2% female and 41.1% male across 94 sites. Program evaluation efforts collected data through pre‐ and post‐program surveys, lesson checklists, and on‐site observations at a subset of sites. IJC surveys assessed participants' cooking self‐efficacy, fruit and vegetable preferences, cooking attitudes, cooking behaviors, and self‐efficacy for selecting and eating healthy foods.ResultsT‐tests revealed that participants who participated in IJC over five consecutive days experienced greater changes in cooking self‐efficacy (t(1162) = −4.05, p < .001), fruit and vegetable preferences (t(1139) = −2.51, p = .012), and cooking behaviors (t(1105) = −1.89, p = .059). Students who had participated in a cooking program before scored higher at baseline in cooking self‐efficacy (t(697) = −3.73, p < .001) and cooking behaviors (t(560) = −4.52, p < .001), but students who had not participated in a cooking program before experienced greater changes in cooking self‐efficacy (t(706) = 4.14, p < .001) and fruit and vegetable preferences (t(708) = 2.05, p = .041) as a result of the program. Correlational analyses revealed that the student to teacher ratio was negatively related to changes in fruit and vegetable preferences (r(959) = −.098, p = .002), such that the fewer students per teacher, the greater the positive change in participants' fruit and vegetable preferences. The number of hours of programming was also positively related to changes in fruit and vegetable preferences (r(1016) = .077, p = .015) and self‐efficacy for selecting and eating healthy foods (r(984) = .095, p = .003).ConclusionsLonger lesson hours and a more concentrated learning schedule resulted in positive changes in participants' dietary attitudes and behaviors. Participants who had not participated a cooking program previously benefited more from IJC. Work going forward with this program should encourage sufficient program hours and completion of the program within five consecutive days.Support or Funding InformationJessica Jarick Metcalfe is supported by the Agriculture and Food Research Initiative of the USDA National Institute of Food and Agriculture under the Illinois Transdisciplinary Obesity Prevention Program grant (2011‐67001‐30101) to the Division of Nutritional Sciences at the University of Illinois.