Nutrition and Lifestyle Changes in Patients With Previously Untreated Stage I or Stage II Prostate Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed adenocarcinoma (small cell acinar type) of the prostate * Has undergone an extended pattern biopsy (defined as 8+ cores) within the past 2 years OR is scheduled to undergo an extended pattern clinical biopsy within 6 weeks of starting study intervention and is willing to undergo 4 additional research core biopsies * No more than 33% of biopsy cores positive (\> 33% of biopsy cores positive allowed if due to microfoci of adenocarcinoma) * No more than 50% of the length of a tumor core involved by carcinoma * Clinical stage T1 or T2a disease * Previously untreated disease * Gleason score ≤ 6 with no pattern 4 or 5 histology (Gleason pattern 4 seen as a microfocus \[\< 2 mm in length\] allowed) * Prostate-specific antigen (PSA) ≤ 10.0 ng/mL (PSA \< 15 ng/mL allowed for patients with benign prostatic hyperplasia or prostatitis) * Must have had 3 serum PSA levels performed ≥ 2 weeks apart over the past year to allow calculation of a PSA doubling time * No PSA doubling time of \< 3 months * Has chosen watchful waiting as treatment PATIENT CHARACTERISTICS: * ECOG performance status 0-2 * Life expectancy \> 3 months * Living in the greater San Francisco Bay Area * Willing to make comprehensive lifestyle changes * Baseline dietary fat intake ≥ 15% * Able to participate in the exercise portion of this study, as determined by the cardiologist or primary care physician * No limited exercise tolerance precluding participation in the lifestyle intervention component of this study * No comprehensive lifestyle change similar to the lifestyle intervention used in this study * No concurrent uncontrolled illness including, but not limited to, any of the following: * Ongoing or active infection * Symptomatic congestive heart failure * Unstable angina pectoris * Coronary artery disease requiring a revascularization procedure * Cardiac arrhythmia * Psychiatric illness/social situation that would limit compliance with study requirements PRIOR CONCURRENT THERAPY: * No prior or other concurrent treatment for prostate cancer, including any of the following: * Surgery * Radiotherapy * Hormonal therapy (e.g., leuprolide acetate, bicalutamide, flutamide, goserelin, megestrol acetate, nilutamide, or DES/estrogen) * Chemotherapy * PC-SPES * Investigational agents * More than 4 weeks since prior and no concurrent finasteride or dutasteride * More than 4 weeks since prior and no concurrent saw palmetto or any other herbal/nutritional preparation that would affect hormone levels * More than 4 weeks since prior multivitamin/mineral and/or supplemental soy protein, vitamin E, vitamin C, selenium, fish oil, or any other preparation intended to supplement levels of omega-3 unsaturated fatty acids * More than 1 month since prior and no concurrent NSAIDs, COX-2-inhibitors, and/or aspirin used for \> 7 consecutive days