Use of early time-restricted eating to promote weight loss and improve cardiometabolic health in postpartum women - PROJECT SUMMARY/ABSTRACT The overall goal of this 5-year K23 proposal is to support Camille Schneider Worthington, PhD, RD to become an independent clinical investigator with a research program focused on behavioral interventions for promoting maternal-child cardiometabolic health. The postpartum period is a critical time for intervening to improve maternal-child health. Existing behavioral postpartum weight management interventions have had modest success, particularly among women with overweight/obesity (Ow/Ob; body mass index ≥ 25 kg/m2). Timing of energy intake may contribute to weight gain and worsening metabolic health postpartum, but no studies have examined the effects of altering the timing of energy intake to manage postpartum weight and its metabolic consequences. Time-restricted eating, which is a form of intermittent fasting that involves restricting the daily ingestive period to ≤10 hours, has received considerable attention for promoting weight loss. Early time-restricted eating (eTRE) appears to be particularly beneficial as it is a form of time-restricted eating that involves shifting the majority of caloric intake earlier in the day to align with circadian rhythms in metabolism (i.e., chrononutrition). eTRE is a simple, focused dietary approach which may confer benefits behaviorally (e.g., improved adherence) and physiologically (e.g., improved insulin sensitivity) that are especially relevant postpartum. Yet, an eTRE intervention for improving cardiometabolic health postpartum has not been studied. To begin addressing this gap, Dr. Worthington received an institutional grant and is currently collecting dietary data and qualitative feedback from postpartum women to inform the development of a postpartum-adapted eTRE intervention (completion date: 6/2023). The proposed K23 will then be used to test the feasibility of the eTRE intervention among postpartum women with Ow/Ob. The proposed 2-arm pilot randomized trial (N=60) is rigorously designed to accomplish the following Specific Aims: Aim 1: Determine the feasibility and acceptability of a 12-week eTRE intervention among postpartum women with Ow/Ob. Aim 2: Examine the preliminary effects of the eTRE intervention on weight, body composition, and insulin sensitivity. Aim 3: Investigate the preliminary effects of the eTRE intervention on energy intake, appetite, and fatigue. Through this proposal, Dr. Worthington will accomplish the following training objectives: 1) Develop advanced knowledge and experience in behavioral intervention trial design, implementation, and adaptation; 2) Develop skills and experience in chrononutrition and underlying circadian and physiological mechanisms; 3) Develop advanced skills and hands-on experience in qualitative research methods; 4) Professional development and progress to research independence. This proposal represents a 5-year comprehensive mentoring, training, and research plan to transition the candidate to a successful independent clinical investigator. By the end of the award period, Dr. Worthington will have contributed novel data in the growing field of chrononutrition and maternal-child health and have submitted a competitive R01 to evaluate the clinical and cost-effectiveness of the refined postpartum eTRE intervention.