 A randomized, crossover design, acute study was completed in 21 healthy adults age 23 1 y; BMI: 23.8 0.6 kgm2 to compare 400 kcal lunch meals varying in protein quality. Two separate comparisons were performed. The first comparison consisted of macronutrient and fiber-matched lunches which varied in protein quality: 24 g beef protein vs. 24 g soy protein. The second comparison matched serving size only: 1 serving of beef 24 g protein with 0 g fiber vs. 1 serving of soy 14 g protein; 5 g fiber. For each treatment, the participants completed 2 testing days per lunch treatment. During the Appetite Assessment Days, each participant reported to the lab to consume one of the lunch meals. Pre and 7-h post-lunch appetite and cravings questionnaires were completed throughout each testing day along with plasma, hormonal responses, and plasma amino acid concentrations through repeated blood sampling. Ad libitum dinner energy intake was also measured. During the Reward Assessment Days, the participants reported to our facility to again consume one of the lunch meals. Pre and post-lunch neural responses to food stimuli, through functional magnetic resonance imaging fMRI, occurred followed by ad libitum consumption of a lunch dessert. 