Time-Restricted Eating Versus Nutritional Counseling for the Reduction of Radiation or Chemoradiation Tx Side Effects in Patients With Prostate, Cervical, or Rectal Cancers

Inclusion Criteria: * Male and female patients aged 18 or older * Localized high risk prostate cancer or node positive prostate cancer histologically confirmed by biopsy or recurrence after surgical resection planning to receive whole pelvis radiation therapy +/- androgen deprivation therapy or * Locally advanced cervical cancer receiving whole pelvic/paraaortic radiation therapy + concurrent cisplatin-based chemotherapy or * Locally advanced rectal cancer receiving whole pelvis radiation therapy + concurrent 5FU/capecitabine * Eastern Cooperative Oncology Group (ECOG) Performance Status 0-2 * Able to provide a written consent for study participation Exclusion Criteria: * PROSTATE CANCER: Prior radiation therapy to the prostate gland or pelvis * PROSTATE CANCER: Prior therapy with androgen deprivation therapy for longer than 6 months * PROSTATE CANCER: Prior chemotherapy * PROSTATE CANCER: Men with diabetes may enroll, provided they are on stable doses of antihyperglycemic medication for at least 6 months and provided the physician managing their diabetes feels they can safely hold antihyperglycemic medication during daily time-restricted eating * PROSTATE CANCER: Must be eligible to receive neoadjuvant and concurrent androgen deprivation therapy, but androgen deprivation therapy is not required * PROSTATE CANCER: Men whose treatment plan includes up-front docetaxel will be excluded due potential confounding * PROSTATE CANCER: Patients whose body mass index (BMI) is less than 21 at time of screening * PROSTATE CANCER: Men who are currently undergoing a strict macronutrient or time limited diet including ketogenic, low-carbohydrate (carb), paleolithic (paleo), or warrior diet are excluded * GYNECOLOGIC CANCER: Prior radiation therapy to the cervix, uterus or pelvis * GYNECOLOGIC CANCER: Prior chemotherapy * GYNECOLOGIC CANCER: Women must not be pregnant, planning to become pregnant or lactating at the time of enrollment or during the course of the study * GYNECOLOGIC CANCER: Women with diabetes may enroll, provided they are on stable doses of antihyperglycemic medication for at least 6 months and provided the physician managing their diabetes feels they can safely hold antihyperglycemic medication during daily time-restricted eating * GYNECOLOGIC CANCER: Must be eligible to receive chemotherapy that is cisplatin based * GYNECOLOGIC CANCER: Patients whose BMI is less than 21 at time of screening * GYNECOLOGIC CANCER: Women who are currently undergoing a strict macronutrient or time limited diet including ketogenic, low-carb, paleo, or warrior diet are excluded * RECTAL CANCER: Prior pelvic radiation therapy * RECTAL CANCER: Prior chemotherapy * RECTAL CANCER: Patients with diabetes may enroll, provided they are on stable doses of antihyperglycemic medication for at least 6 months and provided the physician managing their diabetes feels they can safely hold antihyperglycemic medication during daily time-restricted eating * RECTAL CANCER: Patients whose BMI is less than 21at time of screening * RECTAL CANCER: Women must not be pregnant, planning to become pregnant or lactating at the time of enrollment or during the course of the study * RECTAL CANCER: Patients who are currently undergoing a strict macronutrient or time limited diet including ketogenic, low-carb, paleo, or warrior diet are excluded