Recruiting

Daily Eating Patterns

Sponsor:

The University of Tennessee, Knoxville

Code:

NCT06455995

Conditions

Obesity

Eligibility Criteria

Sex: All

Age: 25 - 60

Healthy Volunteers: Not accepted

Interventions

DEPTH

DEPTH-Morning

DEPTH-Evening

Study Details

Brief summary:

The goal of this randomized controlled trial is to learn how the time of day when calories are eaten affects weight loss in the long-term (12 months). The main aims are to learn:

1. The influence of time-based energy intake goals on longer-term weight loss.
2. The influence of time-based energy intake goals on eating temporal patterns, sleep regularity, and appetite regulation.

Researchers will compare whether goals to eat most of a person's calories in the morning or evening work to treat obesity.

Participants will:

1. Eat a reduced-calorie, low-fat diet (some participants will have goals to eat their calories at certain times of day based on their group)
2. Be physically active at least 200 minutes
3. Receive a cognitive behavioral intervention

Conditions

Obesity

Study ID

NCT06455995

Start date

Jul 16, 2024

Status verified date

Jun, 2026

Completion date

Dec, 2028

Anticipated

Primary completion date

Dec, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 25 - 60

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Body mass index (BMI) between 27 and 45 kg/m2.

Exclusion Criteria:

  • Report not regularly (>/= 5 days/wk) consuming energy (>/= 100 kcal) prior to 12 pm, and not being able to consume energy every day (>/= 50 kcal) within one hour of awakening.
  • Report taking sleep medication or not regularly (>/= 5 nights/wk) getting at least 6 hrs of total sleep.
  • Report being a shift workers/alternative shift workers that work outside of 7 am and 7 pm.
  • Report being diagnosed with type 1, or type 2 diabetes and taking medication that requires eating to occur at certain time periods.
  • Report a heart condition, chest pain during periods of activity or rest, or loss of consciousness on the Physical Activity Readiness Questionnaire (PAR-Q). Individuals reporting joint problems, prescription medication usage, or other medical conditions that could limit exercise will be required to obtain written physician consent to participate.
  • Report being unable to walk for 2 blocks (1/4 mile) without stopping.
  • Report major psychiatric diseases or organic brain syndromes.
  • Report currently participating in a weight loss program and/or taking weight loss or appetite regulation medication or lost >/= 5% of body weight during the past 6 months.
  • Report having bariatric surgery for weight loss/planning to have bariatric surgery in the next 12 months.
  • Report being pregnant, lactating, < 6 months post-partum or plan to become pregnant (next 12 months).
  • Report planning to move outside of the metropolitan area within the time frame of the investigation.
  • Do not have daily access to PC with internet or smartphones (needed for self-monitoring).

Study Design

Enrollment

174 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

active comparator: DEPTH-Standard

Participants in the Standard Group will receive a reduced-energy, low-fat dietary prescription (1200-1500 kcal/d, < 30% energy from fat), physical activity goals (> 200 min/wk of moderate- to vigorous-intensity physical activity \[MVPA\]) and a cognitive behavioral intervention. Standard group will receive no guidance on energy intake distribution (standard lifestyle intervention).

experimental: DEPTH-Morning

Participants in the Morning Group will receive a reduced-energy, low-fat dietary prescription (1200-1500 kcal/d, < 30% energy from fat), physical activity goals (> 200 min/wk of moderate- to vigorous-intensity physical activity \[MVPA\]) and a cognitive behavioral intervention. They will also have time-based energy intake goals of 70% of kcal within the first 6 hrs of the eating window and 30% of kcal within the last 6 hrs of the eating window (a morning-loaded energy distribution).

experimental: DEPTH-Evening

Participants in the Evening Group will receive a reduced-energy, low-fat dietary prescription (1200-1500 kcal/d, < 30% energy from fat), physical activity goals (> 200 min/wk of moderate- to vigorous-intensity physical activity \[MVPA\]) and a cognitive behavioral intervention. They will also have time-based energy intake goals of 30% of kcal within the first 6 hrs of the eating window and 70% of kcal within the last 6 hrs of the eating window (an evening-loaded energy distribution).

Interventions

DEPTH

All conditions will receive a reduced-energy, low-fat dietary prescription (1200-1500 kcal/d, < 30% energy from fat), physical activity goals (> 200 min/wk of moderate- to vigorous-intensity physical activity \[MVPA\]) and a cognitive behavioral intervention. To minimize the effect of other eating temporal variables on outcomes, guidance on the eating window length and the number of eating occasions in the day will be consistent across all three conditions. Thus, the three conditions will be instructed to have their first eating occasion < 60 minutes of awakening, and eat their three meals and one snack within a 12-hr eating window.

DEPTH-Morning

Morning will also have time-based energy intake goals of 70% of kcal within the first 6 hrs of the eating window and 30% of kcal within the last 6 hrs of the eating window (a morning-loaded energy distribution).

DEPTH-Evening

Evening will also have time-based energy intake goals of 30% of kcal within the first 6 hrs of the eating window and 70% of kcal within the last 6 hrs of the eating window (an evening-loaded energy distribution).

Primary outcome measure

  • Percent Weight Change [ Time Frame: 0, 3, 6, and 12 months ]
  • Body Mass Index (BMI) [ Time Frame: 0, 3, 6, and 12 months ]

Central Contacts and Locations

Central contacts

Hollie A Raynor, PhD

865-974-9126hraynor@utk.edu

Locations

Healthy Eating and Activity Laboratory

Recruiting

Knoxville, Tennessee, United States, 37996

More Information

Sponsor

The University of Tennessee, Knoxville

Last update posted

Jun 15, 2026

Last verified

Jun, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by The University of Tennessee, Knoxville on 2026-06-15.