Time-restricted Eating, Appetite and Sleep

The goal of this clinical trial is to learn about the effect of time-restricted eating (TRE) to 10 hours per day on the regulation of appetite, the desire to eat, and the quality and duration of nocturnal sleep in adults with normal weight and short sleep duration and/or habitual poor quality sleep.

The main questions it aims to answer are: 1) How does a time-restricted eating protocol affect appetite and desire to eat? and 2) How does a time-restricted eating protocol affect nighttime sleep duration and quality? Participants will be asked to follow a TRE protocol on which they must restrict their eating to a self-selected time window of 10 hours per day (but with mandatory fasting from 11 p.m. to 6 a.m.) for 2 months. Researchers will compare the intervention with a control group, in which the participants should follow their usual diet without any time restriction, to see if the intervention decreases appetite and desire to eat, improves the quality, and increases sleep duration.

Time-restricted eating (TRE) restricts the time to consume food during the day, establishing a feeding window (thus extending the fasting period). It has been suggested that TRE may regulate appetite and sleep quality, even though the evidence is equivocal for these last two aspects. This study aims to determine the effect of TRE (to 10 hours per day) on regulating appetite, the desire to eat, and the quality and duration of nocturnal sleep in normal-weight adults with short-duration and/or habitual poor-quality sleep.

The study sample will be composed of at least 24 participants, randomly assigned to an intervention (TRE) or no-intervention (Control) group. Participants will be recruited in the Santiago Metropolitan region (near the Faculty of Medicine of the University of Chile, Independencia commune) through an open call to participate (through flyers and on social networks). The groups being randomly compared are: i) TRE (intervention group), in which participants must restrict their eating to a time window of 10 hours per day, with mandatory fasting from 11 p.m. to 6 a.m.; and ii) Control (no-intervention group), in which the participants should follow their usual diet, without any time restriction. Both groups will be evaluated before, during, and after 2 months.

In both groups, the following main parameters will be evaluated: i) appetite and satiety feelings (through visual analog scales) and the intense desire to eat (through a Food Craving inventory); ii) the quality of habitual sleep during the last month (through the Pittsburgh Sleep Quality Index) and, nighttime sleep duration (through 7-days actigraphy recordings); iii) diet composition and quality (through 24-h recall). Measurements of anthropometry and body fat will also be implemented.

Eligibility Criteria:
Inclusion Criteria:

* Young (age between 18 to 45 years)
* Healthy adults
* Both women and men
* Body-mass index between 18.5 to 24.9 kg/m2
* Report sleeping less than 7 hours per night and/or who have poor sleep quality.

Exclusion Criteria:

* Night shift workers
* Patients with psychiatric disorders
* Patients with neurological diseases
* Patients with uncontrolled thyroid disease
* Lactating and pregnant women
* Patients with type-1 or type-2 diabetes
* Persons with high blood pressure or hypertension
* Patients with uncontrolled dyslipidemia
* Patients with sleep disorders
* Persons who perform intense physical exercise more than 3 times a week