Time-Restricted Eating for Obesity

Overseen By Stephanie T Chung, M.D.

Age: 18 - 65

Sex: Female

Trial Phase: Academic

Sponsor: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Must not be taking: Antihyperglycemics, Steroids, Adrenergics, others

Disqualifiers: Diabetes, Thyroid disease, Pregnancy, others

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

Compensation: Varies

Number of Visits: 2

150 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how time-restricted eating (TRE), which involves eating only during specific hours, affects women's health. Researchers aim to understand how women of different body sizes respond to TRE. The study seeks women in good health, with regular menstrual cycles, and a BMI indicating either a healthy weight or obesity. Participants will stay in a clinic, follow a TRE schedule, and undergo various health assessments. The results will help determine TRE's impact on women's metabolism and overall health. As an unphased study, this trial offers participants the chance to contribute to groundbreaking research on women's health and metabolism.

Will I have to stop taking my current medications?

The trial requires that participants do not use certain medications, including those for blood sugar control, steroids, and medications affecting sleep or metabolism. If you are taking any of these, you may need to stop before joining the study.

What prior data suggests that time-restricted eating is safe for women?

Research has shown that time-restricted eating (TRE) is generally safe for most people. Studies have found that TRE can aid in weight loss and improve how the body processes food. For example, one study found that people burned more fat when they ate meals earlier in the day. Another study showed that TRE helped overweight and obese women lose weight and lower their fasting insulin levels without affecting their muscle mass.

These findings suggest that TRE is well-tolerated, with no major safety concerns reported in these studies. It's important to note that TRE involves changing when you eat, not what you eat, which may make it easier to follow without causing harm.

As with any change in diet, consulting a healthcare provider is advisable, especially if there are any health conditions or concerns. ^{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 unique approach compared to conventional dietary regimens. Unlike traditional methods that focus on calorie counting or specific food types, time-restricted eating simply limits the eating window, potentially making it easier to follow and more sustainable in the long term. This method aligns eating patterns with the body's natural circadian rhythms, which may enhance metabolism and improve weight management. Moreover, by concentrating food intake into a specific timeframe, it can lead to better appetite control and reduced overall caloric intake without the need for strict dietary changes.

What evidence suggests that time-restricted eating might be an effective treatment for obesity?

This trial will compare early time-restricted eating (eTRE) with a conventional dietary regimen. Research has shown that eTRE can aid in weight loss and improve health. One study found that eTRE helped participants lose more weight and lower their diastolic blood pressure, the bottom number in a blood pressure reading, compared to eating over a longer period. Another study showed that eTRE reduced body fat and lowered fasting glucose levels, the sugar in the blood when fasting. Additionally, eTRE has been shown to lower body weight by about 4% and improve insulin levels, aiding in sugar management. These findings suggest that eTRE might be a promising approach to managing obesity and enhancing health. ^{2 6 7 8 9}

Who Is on the Research Team?

Stephanie T Chung, M.D.

Principal Investigator

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Are You a Good Fit for This Trial?

Healthy premenopausal women aged 18-50 with a BMI of either 18-24.9 or over 30, who are willing to follow the study's lifestyle guidelines and procedures for its duration. Exclusions include those with certain metabolic conditions, on specific medications affecting metabolism, heavy caffeine users, irregular sleep/eating patterns, recent weight fluctuations, competitive athletes, alcohol consumers exceeding three drinks daily, and tobacco/nicotine users.

Inclusion Criteria

BMI of 18-24.9 or >=30 kg/m^2

I am in good health overall.

Agreement to adhere to Lifestyle Considerations throughout study duration

Exclusion Criteria

I do not have immune, inflammatory, or metabolic conditions that could affect the study.

Inability to provide informed consent

Food allergies/intolerances or dietary patterns that would prohibit consumption of metabolic diet

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1 day

1 visit (in-person)

Clinic Stay

Participants stay in the clinic for 5 days, following a time restricted eating regimen and undergoing various tests and assessments.

5 days

1 visit (in-person, 5-day stay)

Follow-up

Participants are monitored for safety and effectiveness after the clinic stay, including assessment of ketone metabolism and immunoregulation.

1 week

What Are the Treatments Tested in This Trial?

Interventions

• Conventional dietary regimen (12-hr, 9:30a-9:30p)
• Early Time-Restricted Eating

Trial Overview

The trial is examining how early time-restricted eating (TRE), where participants eat only during a limited part of the day compared to a conventional diet spread over 12 hours affects ketone metabolism and immune function in women. It includes tests like DXA scans and stable isotope tracer studies during a five-day clinic stay.

How Is the Trial Designed?

Group I: Premenopausal women (lean and obese) Experimental Treatment 2 Interventions

Ages 18-50 yearsBMI 18.0-24.5 mg/k\^2 or BMI \> 30 mg/k\^2

Who Is Running the Clinical Trial?

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Lead Sponsor

Trials

2,513

Recruited

4,366,000+

Published Research Related to This Trial

Intermittent energy restriction (IER) was found to be a feasible and effective weight management strategy for adolescents aged 12-17 with obesity, leading to a significant reduction in BMI %95th percentile after 12 weeks (-5.6%) and maintained reductions at 26 weeks.

Participants reported IER as easy and pleasant to follow, indicating high acceptability, and the intervention also resulted in improvements in cardiovascular health markers, such as reduced carotid intima-media thickness and improved flow-mediated dilation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Intermittent Energy Restriction Is a Feasible, Effective, and Acceptable Intervention to Treat Adolescents with Obesity. Jebeile, H., Gow, ML., Lister, NB., et al.[2023]

In a 12-week study involving 20 participants (17 women and 3 men), time-restricted eating (TRE) significantly reduced the eating window and led to weight loss, decreased fat mass, and reduced visceral fat compared to an unrestricted eating control group.

Participants in the TRE group experienced a 3.7% reduction in weight and an 11.1% reduction in visceral fat, demonstrating that TRE can be an effective strategy for weight management without changing physical activity or metabolic measures.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Time-Restricted Eating Effects on Body Composition and Metabolic Measures in Humans who are Overweight: A Feasibility Study. Chow, LS., Manoogian, ENC., Alvear, A., et al.[2020]

Time-restricted eating (TRE), which limits food intake to 6 to 10 hours during the active part of the day, has been shown to improve metabolic health and glucose tolerance in various models, including humans.

Most research on TRE has focused on starting the eating window in the morning, but this paper highlights potential challenges and metabolic effects of delaying the eating window, suggesting that timing may be crucial for maximizing benefits.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Will Delaying Breakfast Mitigate the Metabolic Health Benefits of Time-Restricted Eating? Heilbronn, LK., Regmi, P.[2021]

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]

A time-restricted eating (TRE) intervention designed for people with type 2 diabetes and overweight includes a two-phase approach: an initial strict phase followed by a more flexible phase tailored to individual needs.

Support from healthcare professionals, family, and peers is crucial for maintaining motivation and adherence to the TRE regimen, emphasizing a whole-person approach that considers participants' past experiences.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Designing a Co-created Intervention to Promote Motivation and Maintenance of Time-Restricted Eating in Individuals With Overweight and Type 2 Diabetes. Hempler, NF., Bjerre, N., Varming, AR., et al.[2023]

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]

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]

In a pilot study of 50 participants with obesity over 12 weeks, time-restricted eating (TRE) led to a modest average weight loss of 2.6 kg, with greater weight loss observed in those who adhered to the regimen at least five days a week.

While TRE showed similar weight loss results compared to more complex weight management methods, it did not significantly impact blood pressure or lipid profiles, suggesting its primary benefit may be in weight management rather than metabolic health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Time restricted eating as a weight loss intervention in adults with obesity. Przulj, D., Ladmore, D., Smith, KM., et al.[2021]

Time-restricted eating (TRE) is emerging as a promising strategy for treating obesity and related health issues, addressing the challenges of long-term adherence to traditional hypocaloric diets.

While TRE may help with weight loss and metabolic health through mechanisms like reduced caloric intake and improved eating behaviors, there are significant limitations in current research, including inconsistencies in clinical trials and a lack of long-term safety data.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Time-restricted eating as a novel strategy for treatment of obesity and it's comorbid conditions]. Berkovskaya, MA., Gurova, OY., Khaykina, IA., et al.[2023]

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]

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.

cell.com

cell.com/cell-metabolism/fulltext/S1550-4131(23)00454-0

Time-restricted eating: Watching the clock to treat obesity

showed that 3 months of 10-h TRE (8 a.m.–6 p.m.) lowered body weight by 4%, reduced fasting glucose levels, and decreased HbA1c by 1.5% in ...

5.

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 ...

6.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC9877132/

Early Time-Restricted Eating Affects Weight, Metabolic ...

Data are mixed on whether intermittent fasting improves weight loss and cardiometabolic health. Here, we analyzed the effects of time-restricted eating (TRE) ...

7.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC12479299/

Effects of time-restricted eating on body composition and ...

TRE is effective in reducing body weight and lowering fasting insulin in overweight and obese women, without negatively affecting lean body mass ...

8.

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 ...

9.

mdpi.com

mdpi.com/2072-6643/16/19/3390

The Effects of Time-Restricted Eating on Fat Loss in Adults ...

Subgroup analyses showed that TRE only or TRE-caloric restriction with an eating window of 6 to 8 h may be appropriate for losing body fat and overall weight.