Inclusion Criteria:  Histologically confirmed adenocarcinoma of the prostate that is localized based on prostate magnetic resonance imaging (MRI) and meets National Comprehensive Cancer Network (NCCN) intermediate risk criteria (as follows):  Clinical T2b-T2c or lower disease Gleason Grade group 2 or 3 on biopsy Prostate specific antigen (PSA) =< 20 ng/mL Desires radical prostatectomy (open or robotic) for prostate cancer management and is a surgical candidate as determined by the treating urologic oncologist Adult men > 30 and < 75 years old (African American or non-Hispanic white)  Meet one of the following criteria for overweight or obesity:  Body Mass Index (BMI) between 26 and 39 Waist circumference >= 40 inches Willingness to exclusively consume all the provided meals Willingness to comply with all study procedures and scheduled visits Reside in the greater Houston/outlying areas and/or willing to travel for study-related visits at MD Anderson  Exclusion Criteria:  Major dietary restrictions or food allergies Food aversions or preferences that preclude following a Mediterranean diet, such as unwillingness to eat vegetables, grains, animal products or fish Medical contraindications to the intervention diet as determined by the treating physician Current self-reported smoker or heavy drinker (defined as >14 drinks per week) or current self-reported illicit drug use  Prostate cancer that meets NCCN high and very high risk criteria (as follows):  pT3a or higher disease Grade group 4 or 5 adenocarcinoma of prostate PSA > 20ng/mL