Project Summary/Abstract
Despite great strides in achieving short-term weight loss success, long-term weight loss maintenance (WLM)
remains a challenge. Time-restricted eating (TRE), a form of intermittent fasting, is an untested bio-behavioral
strategy for WLM. The goal of this Pathway to Independence Award (K99/R00) is to accelerate the candidate's
transition to an independent investigator with focused expertise in the development and evaluation of weight
management strategies during WLM. In the K99 phase of this award, the candidate will obtain training in
expertise in behavior maintenance theories and methods, mixed methods and qualitative analyses and appetite
physiology, and conduct pilot studies to develop and test the intervention approach. The candidate will conduct
a pilot randomized controlled trial (n=40 total; 20/arm) to test the feasibility, acceptability, and adherence of two
TRE interventions (=6 h and =10h eating windows). Participants will include adults (25–65y, BMI>20.5 kg/m2)
recruited from 2 nonsurgical weight loss programs who successfully attained a weight loss of =5% initial body
weight. Prior to randomization, participants will undergo a run-in phase that includes a 4-week weight stabilization
period. The candidate will evaluate the feasibility and acceptability in terms of recruitment, retention, and
adherence to the eating window using a mixed-methods design (Aim 1). The candidate will perform qualitative
interviews (n=12/arm) following completion of the TRE to capture participants' experience with TRE and
determine individual-, family-, and neighborhood/community-level barriers and facilitators to each TRE
intervention, such as motivation, cultural factors, occupation, and family structure (Sub-aim 1) that will be used
to strengthen the intervention. In the R00 phase, the candidate will use acquired skills and training to test the
optimum TRE intervention identified from the K99 phase. In a randomized controlled trial, the candidate will
assess the efficacy of the selected TRE on body weight regain (Aim 2a), and fat mass regain (Aim 2b) at 12
months. The candidate will recruit adults with recent non-surgical weight loss and weight stabilization (similar to
K99 phase). Participants will be randomized to one of 2 arms (n=72 total; n=36/arm): 1) TRE (selected from the
K99 phase) or 2) baseline advice control (CON). Both the TRE and CON groups will be provided with baseline
written materials and strategies that promote successful WLM. Participants in the TRE group will be instructed
to self-monitor dietary intake and body weight in a smartphone application and receive behavioral counseling.
Measurements will be obtained at baseline (0), 3, 6, and 12 months. The primary outcome is body weight regain
at 12 months. The candidate will explore the effects of randomization assignment and WLM on appetite
biomarkers and subjective appetite via a visual analog scale at 6 mos and 12 mos (Exploratory Aim). Ultimately,
this will establish the candidate as an independent investigator conducting interdisciplinary bio-behavioral
research using lifestyle interventions to become a leader in WLM.