Time Restricted Eating for Obesity

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: Mayo Clinic

Must not be taking: Insulin, Sulfonylureas, Weight loss drugs

Disqualifiers: Cancer, Breastfeeding, Pregnant, Eating disorders, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

Duration: 12 weeks

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how eating at different times of the day affects weight and quality of life for people with obesity. Participants will follow one of two eating schedules: either from 8:00 AM to 4:00 PM (early time-restricted eating) or from 12:00 PM to 8:00 PM (late time-restricted eating). The trial aims to determine if meal timing can aid weight management and identify any challenges with these schedules. It seeks individuals with a BMI of 25 or higher who do not regularly skip meals. As an unphased trial, it offers a unique opportunity to contribute to understanding how meal timing impacts health and well-being.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but you cannot participate if you are taking insulin, sulfonylurea drugs, or weight loss medications.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Studies have shown that time-restricted eating (TRE) is generally safe. Research on early time-restricted eating suggests it aids weight loss and may improve mood and blood pressure. These studies reported no major safety issues. Participants mainly experienced benefits such as weight loss and improved well-being.

Late time-restricted eating has also been studied. It led to modest weight loss and helped control insulin levels, crucial for managing energy use. Again, no significant safety concerns emerged.

Both methods involve eating only during specific hours of the day. Research suggests they are well-tolerated, with no serious side effects noted. Most people reported no major problems when following these eating patterns. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about time-restricted eating for obesity because it offers a fresh approach to weight management, distinct from traditional methods like calorie counting or medication. This method focuses on when you eat rather than what you eat, potentially making it easier for people to integrate into their daily lives. The trial explores two different eating windows: early (8:00 AM to 4:00 PM) and late (12:00 PM to 8:00 PM), allowing researchers to understand how timing impacts metabolism and weight loss. By aligning eating patterns with the body's natural circadian rhythms, this approach may enhance metabolic health and improve weight loss outcomes.

What evidence suggests that this trial's treatments could be effective for obesity?

This trial will compare early time-restricted eating (eTRE) with late time-restricted eating (lTRE) for obesity. Research has shown that eTRE, where participants eat between 8:00 AM and 4:00 PM, is effective for weight loss. Studies have found that eTRE not only aids in weight loss but also improves diastolic blood pressure and boosts mood. It also helps reduce body fat and lower fasting blood sugar levels.

For lTRE, where participants eat between 12:00 PM and 8:00 PM, some studies suggest that limiting eating times can generally support weight loss and heart health. However, eating later in the day might not be more effective than spreading meals throughout the day. Both early and late time-restricted eating can aid in weight loss, but early time-restricted eating appears slightly more effective. ^{1 6 7 8 9}

Who Is on the Research Team?

Bradley Bohn, MD

Principal Investigator

Mayo Clinic

Are You a Good Fit for This Trial?

This trial is for obese adults with a BMI of 25 or higher who are willing to limit their eating to an 8-hour window. It's not suitable for those with cancer, pregnant or breastfeeding women, individuals who regularly skip meals, those on certain diabetes or weight loss medications, and people with a history of eating disorders.

Inclusion Criteria

- BMI ≥ to 25.

BMI ≥ to 25

Exclusion Criteria

Have a current cancer diagnosis

Currently breastfeeding

Regularly skip meals

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants follow a time-restricted eating schedule for 12 weeks, either early or late window

12 weeks

Baseline and end of study visits

Follow-up

Participants are monitored for changes in weight, cholesterol, glucose, and other health markers

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Early time-restricted eating
• Late time-restricted eating

Trial Overview The study is examining the effects of early versus late time-restricted eating on weight and BMI in obese adults. Participants will be asked to eat only during an 8-hour period each day to see how this impacts their health and quality of life.

How Is the Trial Designed?

Group I: Late time-restricted eating Experimental Treatment 1 Intervention

Subjects window for eating would be between 12:00 PM (noon) and 8:00 PM

Group II: Early time-restricted eating Experimental Treatment 1 Intervention

Subjects window for eating would be between 08:00 AM - 4:00 PM

Who Is Running the Clinical Trial?

Mayo Clinic

Lead Sponsor

Trials

3,427

Recruited

3,221,000+

Published Research Related to This Trial

In a 12-week study involving 23 obese adults, time-restricted feeding (TRF) with an 8-hour eating window was found to be safe, as there were no significant changes in self-reported adverse events or disordered eating patterns.

The study suggests that TRF can effectively support weight loss in obese individuals without negatively impacting their health or body image perception.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety of 8-h time restricted feeding in adults with obesity. Gabel, K., Hoddy, KK., Varady, KA.[2019]

In an 8-week pilot study involving 78 participants with obesity, those following a 14-hour time-restricted eating (TRE) schedule lost an average of 8.5% of their body weight, which was statistically significant compared to a 12-hour TRE group that lost 7.1%.

The 14:10 TRE group also experienced a significant reduction in fasting blood glucose levels by 7.6 mg/dl, indicating potential metabolic benefits, especially for those with elevated blood glucose at baseline.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of time restricted eating on body weight and fasting glucose in participants with obesity: results of a randomized, controlled, virtual clinical trial. Peeke, PM., Greenway, FL., Billes, SK., et al.[2021]

In a study involving overweight and obese young adults, both early time-restricted eating (eTRE) and late time-restricted eating (lTRE) resulted in similar weight loss after 8 weeks compared to a control group.

eTRE was more effective than lTRE in improving several metabolic health markers, including reducing systolic blood pressure, glucose levels, fasting insulin, insulin resistance, and thyroid axis activity, while lTRE only reduced leptin levels.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Randomized controlled trial for time-restricted eating in overweight and obese young adults. Zhang, LM., Liu, Z., Wang, JQ., et al.[2022]

Time-restricted eating (TRE) is a promising dietary strategy that can help improve metabolic health and restore circadian rhythms, potentially aiding in the prevention and treatment of obesity and its complications.

Current evidence from previous TRE trials suggests a need for more extensive clinical research, including large-scale controlled trials, to fully understand the efficacy and mechanisms of TRE in humans.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Research progress on the application of time-restricted eating in adult obesity and related metabolic diseases]. He, JH., Sun, CY., Liang, C.[2022]

This study is the first to evaluate the effects of time-restricted eating (TRE) on weight loss in a controlled manner, comparing it to a usual eating pattern (UEP) while ensuring both groups consumed the same number of calories and identical diets.

Participants aged 21-69 with prediabetes and obesity were monitored closely, allowing for a rigorous assessment of how meal timing impacts weight change without altering caloric intake.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Design and Implementation of a Time-Restricted Eating Intervention in a Randomized, Controlled Eating Study. White, K., Wu, B., Pilla, SJ., et al.[2023]

In a study involving 99 participants over three months, time-restricted eating (TRE) did not show significant differences in obesity-related outcomes based on the timing of food intake, whether early, medium, or late.

Participants who started eating earlier had a longer eating duration but the late eaters had a longer fasting period, suggesting that the timing of food intake may not be as crucial as previously thought, and further research is needed to clarify these findings.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Early or Delayed Onset of Food Intake in Time-Restricted Eating: Associations with Markers of Obesity in a Secondary Analysis of Two Pilot Studies. Kesztyüs, D., Cermak, P., Kesztyüs, T., et al.[2023]

A survey of 213 families attending pediatric weight management programs found that 66% of parents were interested in trying time-limited eating (TLE) for 12 hours a day, indicating a strong acceptability of this dietary approach among families.

Interest in TLE decreased significantly when the eating window was limited to 10 hours (39%) or 8 hours (26%), suggesting that flexibility in the eating schedule may enhance adherence to dietary interventions for childhood obesity.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Acceptability of Time-Limited Eating in Pediatric Weight Management. Tucker, JM., Siegel, R., Murray, PJ., et al.[2023]

In a study of 50 adults with overweight and obesity, participants successfully reduced their eating window from an average of 16 hours to about 12 hours over a 90-day time-restricted eating (TRE) intervention, leading to significant weight loss and reductions in waist circumference and blood pressure.

The TRE approach, which required no dietary counseling and was monitored through a smartphone app, showed a feasible and effective way to improve eating patterns and health outcomes in this population.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A Smartphone Intervention to Promote Time Restricted Eating Reduces Body Weight and Blood Pressure in Adults with Overweight and Obesity: A Pilot Study. Prasad, M., Fine, K., Gee, A., et al.[2021]

Time-restricted feeding (TRF) significantly reduced body weight and body mass index (BMI) in female college students with hidden obesity over an 8-week period, but it also led to increased blood lipid levels and decreased lean tissue mass.

Combining TRF with exercise did not provide additional benefits compared to TRF or exercise alone, indicating that TRF may not be the most effective strategy for fat reduction in this population.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of time-restricted feeding and walking exercise on the physical health of female college students with hidden obesity: a randomized trial. Liu, H., Chen, S., Ji, H., et al.[2023]

Citations

1. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/35939311/

Effectiveness of Early Time-Restricted Eating for Weight Loss ... In this randomized clinical trial, eTRE was more effective for losing weight and improving diastolic blood pressure and mood than eating over a window of 12 or ...

2. jamanetwork.com jamanetwork.com/journals/jamainternalmedicine/fullarticle/2794819

Effectiveness of Early Time-Restricted Eating for Weight ... In this randomized clinical trial, eTRE was more effective for losing weight and improving diastolic blood pressure and mood than eating over a window of 12 or ...

3. sciencedirect.com sciencedirect.com/science/article/pii/S0261561425000950

Randomized Control Trials Early time-restricted eating with ... Early time-restricted eating with energy restriction has a better effect on body fat mass, diastolic blood pressure, metabolic age and fasting glucose

4. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9361187/

Effectiveness of Early Time-Restricted Eating for Weight ... Early time-restricted eating was more effective for weight loss than eating over a window of 12 or more hours; larger studies are needed on fat ...

5. nature.com nature.com/articles/s41430-023-01311-w

Time-restricted eating with calorie restriction on weight loss ... Subgroup analysis suggested that early TRE is more effective in weight loss (WMD: −1.42, 95% CI: −1.84 to −1.01, and I2: 0%) and improving fat ...

6. sciencedirect.com sciencedirect.com/science/article/pii/S1550413123004540

Time-restricted eating: Watching the clock to treat obesity In participants with obesity, time-restricted eating results in 3%–5% weight loss over 2–12 months, versus controls. Reductions in body weight ...

7. jamanetwork.com jamanetwork.com/journals/jamainternalmedicine/fullarticle/2771095

Effects of Time-Restricted Eating on Weight Loss and Other ... This randomized clinical trial examines the effect of 16:8-hour time-restricted eating on weight loss and metabolic risk markers.

8. nejm.org nejm.org/doi/full/10.1056/NEJMoa2114833

Calorie Restriction with or without Time-Restricted Eating ... Several pilot clinical studies showed that time-restricted eating resulted in reduction over time in the body weight and fat mass in patients ...

9. frontiersin.org frontiersin.org/journals/nutrition/articles/10.3389/fnut.2025.1664412/full

Effects of time-restricted eating on body composition and ... Our findings indicate that TRE significantly improves insulin levels in overweight and obese women, whereas no significant alterations were observed in blood ...