de Medeiros Rego, Maria Luiza2025-05-142025-05-142025-05-13vt_gsexam:43360https://hdl.handle.net/10919/132453In the US, overall dietary quality among adolescents and young adults (18 to 25 years old) is poor, and ultra-processed foods (UPF) represent more than two-thirds of adolescents' total energy intake. Executive functions (EF) are still maturing during adolescence and young adulthood and can influence dietary decision-making and energy intake (EI). To date, no clinical trial has addressed the impact of UPF intake on eating behaviors within this age range. This dissertation aims to determine the effect of 2 weeks of a eucaloric UPF diet, compared to a non-UPF diet, on food amount consumed (grams), energy intake (EI; kcal), and preference (UPF vs. non-UPF) during an ad libitum buffet meal following each diet condition. As an exploratory aim, changes in EF (inhibitory control, working memory, and cognitive flexibility) will be evaluated as a predictor of food amount consumed (grams), energy intake (kcal), and preference (UPF vs. non-UPF) during ad libitum buffet meals. It was hypothesized that the UPF diet would increase food consumption during the buffet meal, as well as the preference for UPF items. Additionally, EF would be positively correlated with non-UPF consumption and negatively correlated with UPF consumption. Participants aged 18 to 25 years underwent two 14-day controlled feeding periods (81% UPF, 0% UPF) using a randomly assigned crossover design, with a 4-week washout between conditions. EF were evaluated before and after each diet. After each diet condition, an ad libitum buffet meal was served, followed by the Eating in the Absence of Hunger. 27 individuals (mean age = 22 ± 2 years, mean BMI = 23.8 ± 3 kg/m2) were included. Diets were equally rated for liking and familiarity. Energy and food intake during the ad libitum buffet meal did not differ between diet conditions. Age and diet randomization order influenced food intake during the ad libitum buffet meal. Inhibitory control may serve as a predictor of the consumption of ad libitum buffet meals. There were no effects of executive function and diet condition on eating in the absence of hunger.ETDenIn Copyrightultra-processed foodseating behaviorsbody weightexecutive functionsDissertation