Feasibility and Acceptability of Time Restricted Eating (TRE) Among Native Hawaiian/Pacific Islander Women at Risk for Endometrial Cancer

Enrollment: The study includes two phases. Phase 1 includes focus groups among 30 Native Hawaiian/Pacific Islander women at risk of endometrial cancer. Focus groups will determine sociocultural influences on (i) dietary behavior including meal timing; (ii) dietary preferences; (iii) proposed meal plans and intervention design; (iv) perceptions of weight loss and body image. In the second study phase, the study team will recruit 10 Pacific Islander women to participate in a 14-week randomized dietary crossover study. Each woman will participate in both intervention arms and act as her own control.

Focus Group: To accomplish all aspects of Aim 1 of this study, the study team will recruit 30 Pacific Islander women at risk for endometrial cancer to conduct virtual focus groups. These focus groups will take place via private videoconference, like Zoom, and a language translator will be provided, as necessary. The focus groups will be attended by a Native Hawaiian/Pacific Islander Community Expert. Questions will be designed to understand sociocultural influences on dietary behavior (questions on social eating, meal timing, and dietary preferences, soliciting feedback on study intervention delivery design, and perceptions of weight loss and body image). An icebreaker will be conducted prior to formal questioning. Sessions will be audio-recorded on the videoconference and an additional device, transcribed verbatim, and checked for accuracy. Two additional team members will be present as note takers. Our Community Expert will be present to help facilitate the session. Questions will be provided at the beginning of the session to ensure cultural sensitivity.

Dietary Intervention: The dietary intervention includes 5 study visits, and features a baseline visit, 2-week run-in period, 4-week control diet schedule, 4-week washout period, and a 4-week, 8 to 10-hour Time Restricted Eating (TRE) protocol (8 to 10-hour feeding and 14 to 16-hour fasting periods). A follow-up questionnaire will be mailed 6-months post- intervention. For the control schedule, women will receive frozen lunch and dinner meals and a standardized breakfast and snacks menu. All meals and the breakfast/snack menu will be designed to be culturally competent with feedback from the focus groups, and meal plans will be individualized to meet weight maintenance energy requirements. For the TRE schedule, women will receive prepared frozen lunch and dinner meals as per the control schedule, but will be asked to consume daily meals, snacks, and calorie-containing beverages within an 8 to 10-hour period that fits their schedule. They will be asked to maintain their regular sleep and physical activity schedule. The fasting period will ramp up during the first week (Days 1-3, 12-14 h per day, Days 4-6, 14-16 h per day, Days 7+, 16 h per day). Women will be asked to schedule the eating period at the same time each day. All meals (control and TRE) will be provided by the Metabolic Kitchen located at the University of Utah.

Visit 1: During the baseline visit, a coordinator will obtain consent from the participant, and they will be asked to compete questionnaires asking about clinical and demographic factors, chronotype, and physical activity, and various anthropometric measurements will be taken. Following the baseline visit, participants will undergo a 2-week run-in period. During this time, the goal is to record women's usual times of eating episodes and appetite while following their habitual diet.

Visit 2: Women will provide fasting blood and stool samples, and anthropometric measurements will be taken. Following visit 2, participants will undergo the control or TRE schedule for 4 weeks.