Changes in 24-hour Activity Cycle Behaviors During a Time-Restricted Eating Intervention in College-Aged Women

Time-restricted Eating (TRE) is a dietary approach that limits food intake to 4 - 12-hour windows without intentionally altering diet quality. TRE has several benefits including modest reductions in body weight and fat mass, improved glucose control, and reduced inflammatory markers. While research supports the metabolic and weight related benefits of TRE, there is limited evidence of its effects on physical activity (PA), sedentary behavior (SB) and sleep - the core components of 24-hour Activity Cycle (24-HAC), which is a holistic framework that integrates the three health-related activities. TRE research has largely focused on clinical populations, leaving its feasibility and adherence in healthy younger adults understudied. Within this group, college students' misaligned circadian rhythms and unpredictable schedules may make adherence to TRE challenging, highlighting the need for research on its practicality in this group. These outcomes are also particularly important to investigate in women, considering that SB is more prevalent among college-aged women (69%) compared to men (46%). To address these issues, we will conduct a three-week intervention to study the effects of TRE on the 24-HAC outcomes. College aged women will be screened and enrolled, then assigned to either a control or TRE group. Participants in the TRE group will self-select the timing of their 8-hour eating window which they will maintain throughout the study (with compliance on at least six days per week needed to be considered adherent). The control group will receive a basic nutrition education at the start of the study and will have no restriction on eating times. 24 HAC behaviors will be measured continuously for one-week of baseline measurement and throughout the intervention by wrist-worn ActiGraph GT9X monitors. Participants will also record the timing of their first and last meal each day and receive periodic reminders to report their hunger and satiety ratings using visual analog scales.