Time-restricted Eating for Postpartum Weight Loss

BEHAVIORAL

Early Time-Restricted Eating (eTRE)

12 weeks of eTRE intervention. Study staff will provide 7 support sessions with brief behavioral support, including evidence based strategies of problem-solving, action planning, and motivational interviewing.

BEHAVIORAL

Control

The control group will be instructed to maintain their average eating window for the 12-week period. Study staff will contact participants 7 times to encourage maintenance.

Study Participation Rate

Time frame: Baseline (6-16 weeks postpartum)

Percentage of eligible subjects who agreed to participate out of those who were screened.

Oral Glucose Tolerance Test (OGTT)

Time frame: Baseline (6-16 weeks postpartum), follow-up (18-28 weeks postpartum)

Indices of glucose tolerance and insulin action will be assessed via a 2-hr OGTT. Participants will consume a 75-g glucose load within 5 minutes, which will be timed to begin at each participant's habitual breakfast time. Fasting blood samples will be collected at 15-, 30-, 60-, 90-, and 120-minutes relative to glucose consumption.

Energy Intake

Time frame: Baseline (6-16 weeks postpartum), follow-up (18-28 weeks postpartum)

Dietary intake will be collected at each assessment by 3 self-administered 24-hr recalls on 3 non-consecutive days (2 weekdays, 1 weekend day) using the Automatic Self-Administered 24-hour Dietary Assessment Tool (ASA24), an online platform developed and hosted by the National Cancer Institute. Total energy intake and kcals from each macronutrient will be derived from 24-hr recalls.

Participant Retention

Time frame: Baseline (6-16 weeks postpartum), follow-up (18-28 weeks postpartum)

The proportion of enrolled participants who complete follow-up.

Change in Visceral Fat

Time frame: Baseline (6-16 weeks postpartum), follow-up (18-28 weeks postpartum)

Bioelectrical impedance analysis (BIA) (seca® mBCA 514) will be used to assess visceral adipose tissue.

Participant Adherence to Intervention

Time frame: Collected daily from intervention start (6-16 weeks postpartum) to follow-up (18-28 weeks postpartum)

Adherence to eating window based on responses to daily electronic REDCap surveys that record start and stop time of the eating window.

eTRE Intervention Satisfaction

Time frame: Baseline (6-16 weeks postpartum), follow-up (18-28 weeks postpartum)

Participant satisfaction with the eating schedule will be assessed using a 5-point Likert scale. Long-term eating schedule preferences will be assessed by asking intervention participants at follow-up whether they plan to: (a) continue following the assigned eTRE schedule; (b) follow a modified eTRE schedule \[and specifying what modifications they plan to make\]; or (c) stop eTRE and return to prior meal timing habits. Qualitative data on eTRE intervention satisfaction will be collected at follow-up. These one-on-one interviews will be conducted in-person or remotely via videoconferencing. Topics explored will include participants' typical day during the intervention, experiences with eTRE, adherence barriers/facilitators, intervention satisfaction, and suggested improvements.

Change in Body Weight

Time frame: Baseline (6-16 weeks postpartum), follow-up (18-28 weeks postpartum)

Body weight measured at baseline and follow-up will be used to calculate weight change.

Change in Subjective Appetite

Time frame: Baseline (6-16 weeks postpartum), follow-up (18-28 weeks postpartum)

Subjective ratings of appetite (hunger and satiety) over the past week will be collected at baseline and follow-up using visual analogue scales scored from 0 (less hunger/less satiety) to 100 (more feelings of hunger/more feelings of satiety) based on the response along a 100-mm line.

Self-Reported Fatigue

Time frame: Baseline (6-16 weeks postpartum), follow-up (18-28 weeks postpartum)

Fatigue will be assessed using the NIH's validated 8-item Patient-Reported Outcomes Measurement Information System (PROMIS) Fatigue Short Form (SF) 8a to assess fatigue over the past 7 days. The PROMIS Fatigue SF 8a is scored on a T-score metric with a mean of 50 and standard deviation of 10. The T-score metric is referenced to the US general population with respect to race/ethnicity, age, education, and sex (e.g., T-score of 40 would be one SD below the US general population). A higher PROMIS T-score represents more of the concept being measured (higher score indicates more fatigue).

What is a clinical trial?

A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.

Is it safe to participate?

Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.

Will I be compensated?

Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.

Will I receive a placebo instead of treatment?

When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.

Can I leave a trial if I change my mind?

Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.

How long does a clinical trial last?

Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.