Background: The optimization of treatment for pediatric cancer has increased 5-year survivor rates to over 80%. Currently, there are almost half a million survivors of a pediatric cancer alive in the United States, with numbers increasing worldwide. Despite increased survivorship, pediatric cancer survivors (PCSs) are at high risk for long-term chronic disease, including cardiometabolic dysregulation at an early age due to cancer-related treatments. PCSs often have increased adiposity, perturbation in the gut microbiome, and chronic systemic inflammation compared to age-matched controls. Time-restricted eating (TRE) has emerged as an effective dietary intervention to promote weight loss in individuals with increased adiposity and cardiometabolic disease. Prebiotic supplements may enhance the efficacy of TRE by promoting satiety via the gut microbiome. Given the accessibility of both TRE and prebiotic supplements, this type of dietary intervention may be ideal for young adult PCSs. The purpose of this study was to determine the feasibility and acceptability of 12 weeks of TRE with and without a prebiotic supplement among young adult PCSs. Changes in body weight, body composition, and cardiometabolic disease risk markers were explored. Methods: Feasibility was measured based on recruitment (n = 20), retention (>80%), and adherence to the TRE eating window and prebiotic (>80%), and acceptability was measured based on a validated survey. Body weight, body composition, blood pressure, and additional blood-based cardiometabolic disease risk markers were also measured before and following the intervention. Results: Feasibility was not met based on recruitment (n = 13), but retention and adherence exceeded the a priori hypothesis. Acceptability also met the a priori hypothesis. Improvements were observed in some cardiometabolic disease risk markers, including a significant decrease in fat mass and visceral fat mass in both groups following the intervention. Conclusions: Given the positive outcomes related to retention, adherence, and acceptability, as well as some cardiometabolic disease risk markers, a larger and longer study of TRE and prebiotic supplementation in PCSs is warranted. However, innovative recruitment strategies should be implemented, such as leveraging social media and targeting larger geographical areas, given recruitment challenges.

Increased adiposity and chronic psychosocial stress (CPS) are plausible modifiable contributors of the recent increase in early-onset colorectal cancer (EOCRC). We conducted an 8-week randomized controlled pilot trial evaluating the feasibility and acceptability of time restricted eating (TRE) (daily ad libitum eating between 12-8pm) and Mindfulness ("Mindfulness for Beginners" course from the Calm^® app) among young adults. Participants were randomized to the following groups: TRE (n = 10); Mindfulness (n = 11); TRE & Mindfulness (n = 11); or Control (n = 11). Forty-three participants were randomized. Acceptability of the trial was high and attrition rates were low (7%). Participants completed 92% of the Mindfulness course, and 90-92% were adherent to the TRE intervention. PSS decreased significantly within the TRE, Mindfulness, and TRE & Mindfulness arms from pre- to post-intervention, but not within the Control arm. The TRE & Mindfulness arm had improvements in visceral fat mass, fasting insulin, fasting glucose, HOMA-IR, hemoglobin A1c, and fecal calprotectin, pre- to post-intervention, compared to the TRE and Mindfulness arms. This study was feasible and well-accepted. Results were promising for the combined TRE & Mindfulness protocol showing superior improvements in perceived stress, visceral adiposity, cardiometabolic and inflammatory markers. It is important to note the limited generalizability of our sample.