Background/Objectives: A faster eating rate is associated with increased energy intake and risk of obesity. High consumption of ultra-processed foods (UPFs) is associated with a faster eating rate. Psychobehavioral aspects, such as body image self-perception, eating disorders, and anxiety, may modulate this eating behavior. Therefore, this study examined the moderating role of psychobehavioral factors in the association between meal type (UPF vs non-UPF) and eating rate among individuals with obesity. Methods: It is a secondary analysis of a randomized, parallel clinical trial conducted with 39 adults who have obesity. Participants were assigned to consume either a UPF-only composed meal or a UPF-free meal, both of which were isoenergetic (~550 kcal). Psychobehavioral variables (food addiction—mYFAS 2.0, body image perception and satisfaction—Silhouette Rating Scale, eating disorders—EAT-26, and anxiety—GAD-7) were assessed. Eating rate was measured in kcal/min. Results: Body image perception and satisfaction significantly interacted with the type of meal. In the UPF group, lower body image dissatisfaction was associated with a higher eating rate (β = 4.79 kcal/min; 95% CI: 1.40; 8.19; p = 0.007), while a higher body image perception score was associated with a lower eating rate (β = −4.61 kcal/min; 95% CI: −8.57; −0.65; p = 0.024). No significant associations were observed for food addiction scores, eating disorders or anxiety. Conclusions: Body image modulates the eating rate in the context of UPF consumption. These findings suggest that interventions against obesity should consider individual psychobehavioral characteristics.

Background/Objectives: To evaluate the metabolic and hormonal responses after meals rich in and free of ultra-processed foods (UPF), with high or low energy density (ED), in adults without obesity (body mass index [BMI] between 18.5 and 29.9 kg/m², body fat percentage ≤ 30% for men and ≤42% for women). Methods: Randomized, crossover-controlled feeding trial. Participants were assigned to four conditions (UPF+/ED+, UPF+/ED−, UPF−/ED+, and UPF−/ED−), each receiving two standardized test meals (breakfast and lunch), matched for energy, macronutrients, fiber, saturated fat, free sugar, and sodium. Blood samples were collected after 12 h fasting, and 240 min after each meal completion for quantification of glucose, insulin, triglycerides, ghrelin, and leptin. Results: Nineteen participants (9 females; 22 y mean age; 23.5 kg/m² mean BMI) were included. The UPF condition resulted in a statistically significant increase in postprandial circulating insulin concentrations throughout the day (p = 0.016), without interactions with meal (p = 0.09). No main effects of ED or UPF × ED interactions were observed for any outcome. Conclusions: In this exploratory secondary analysis of a randomized crossover trial, acute UPF consumption resulted in higher postprandial circulating insulin concentrations, independently of ED. These findings require confirmation in adequately powered studies. Brazilian Registry of Clinical Trials (ReBEC), registration number RBR-10gfr3fb.