Time Restricted Eating With or Without a Fiber Supplement for Weight Management in Pediatric Cancer Survivors

Inclusion Criteria: * Age 18-39 years old at time of consent * Completed anti-tumor treatment for pediatric cancer * BMI 25-39.99 kg/m2 * Able to provide (self or guardian) written informed consent and HIPAA authorization for release of personal health information, via an approved UIC Institutional Review Board (IRB) informed consent form and HIPAA authorization. * As determined at the discretion of the enrolling physician or protocol designee, ability of the subject to understand and comply with study procedures for the entire length of the study. Exclusion Criteria: Subjects meeting any of the criteria below may not participate in the study: * Individuals \<18 or \>39 years of age * Individuals on glucoregulatory medication * Individuals with BMI ≥ 40kg/m2 and \< 25kg/m2 * Individuals who are pregnant, trying to become pregnant or breast feeding. A negative serum or urine pregnancy test is required per institutional practice guidelines at screening as well as prior to all DXA scans. * Shift workers who maintain a work schedule that crosses 12:00 am \> 1 day per week * Individuals with a history of eating disorders * Active infection requiring systemic therapy * Uncontrolled HIV/AIDS or active viral hepatitis * Any mental or medical condition that prevents the patient from giving informed consent or participating in the trial. * Other major comorbidity, as determined by study PI * Illicit drug use (excluding self-reported marijuana) or excessive use of alcohol (i.e., \> 2 drinks/day) * Currently participating in Weight Watcher's or another weight loss program with a ≥ 3% weight loss in three months prior to recruitment * History of: Myocardial infarction, Stroke, Congestive heart failure, Chronic hepatitis, Cirrhosis, Chronic pancreatitis * History of solid organ transplantation * Individual does not have access to the Internet * Individuals who have taken antibiotics \< 2 months prior to the initiation of the study * Individuals who regularly use (≥ 3 times per week) prebiotics, probiotics, synbiotics, prebiotic supplements or laxatives within the past month