Intermittent Fasting

This clinical trial compares two different weight-loss programs, daily continuous calorie energy reduction (CER) versus (vs.) 5:2 intermittent fasting (IF), in preventing progression of kidney (renal) cancer among patients with one or more small renal masses (SRM) undergoing active surveillance (AS). Kidney cancer patients tend to have changes in metabolism that may increase body weight, but weight-loss strategies that work for best for these patients are unknown. The CER program requires a set daily limit for calories. The IF program requires fasting for 2 days a week and normal eating for the remaining 5 days. Both will include self-monitoring with interventionist feedback. This trial may help researchers determine whether the IF program works better than the CER program in improving weight loss, physical health, and/or reducing the risk of kidney cancer progression among patients with small renal masses undergoing AS

The goal of this clinical trial is to see if timed fasting (periods of time that you don't eat) in participants who are receiving chemotherapy prior to surgery is achievable, safe and can improve quality of life, symptoms and outcomes (results) compared to participants who receive standard dietary recommendations in individuals being treated for epithelial ovarian cancer . The main questions it aims to answer are: * Is it feasible to use intermittent fasting during neoadjuvant chemotherapy? * Is it safe to use intermittent fasting during neoadjuvant chemotherapy? * Do participants find it acceptable to use intermittent fasting during neoadjuvant chemotherapy? Researchers will compare participants who receive standard dietary recommendations to see which method is more achievable, safe, and able to improve quality of life, symptoms and outcomes. Participants will: * Receive either the fasting intervention (schedule of times when you do not eat) or standard diet recommendations for 6-9 weeks prior to your surgery starting with the second cycle of chemotherapy. * All participants will be asked to complete chemotherapy and surgery, cancer imaging, baseline screening tests, nutritional assessments, food diaries, blood tests, and surveys about wellbeing. * Participants in the intervention group will be asked to follow a fasting schedule that consists of not eating for 16 hours a day followed by normal eating for the remaining 8 hours of the day for 5 days in a row followed by 2 days of regular eating each week.

This single-arm study is designed to test the hypothesis that a six-month intermittent fasting (IF) intervention is feasible for patients to adhere to and improves health-related quality of life while subjects are on adjuvant endocrine therapy (AET).