Time-Restricted Eating for Obesity

Overseen By Ashley Rosander, BS

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of California, San Diego

Must not be taking: Insulin, Anti-diabetics, Appetite suppressants, others

Disqualifiers: Diabetes, Pregnancy, Heart failure, others

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 aims to explore how time-restricted eating might help people with obesity improve their health. Participants will either follow their usual routine with standard nutritional counseling (standard of care) or eat all their meals within a 10-hour window each day for 12 weeks. This trial suits individuals with a body mass index (BMI) of 30 or more who typically eat for over 14 hours a day and have a smartphone.

As an unphased trial, this study offers a unique opportunity to contribute to innovative research that could lead to new health strategies for obesity.

Do I need to stop my current medications for the trial?

The trial does not specify that you need to stop your current medications, but if you are on cardiovascular medications like statins or anti-hypertensive drugs, you cannot change the dose during the study.

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

Research shows that time-restricted eating (TRE), where eating occurs only during certain hours each day, may help manage obesity. Studies on TRE in humans generally find it well-tolerated. In one clinical trial, participants followed a 16:8-hour TRE pattern (16 hours of fasting and 8 hours of eating) and did not experience any major side effects. This suggests that TRE is safe for most people, though some might initially feel mild hunger or tiredness.

Early studies also suggest that TRE might lower the risk of conditions related to obesity, such as diabetes and heart disease. However, because these studies were small, more research is needed to understand the long-term safety and effects. Overall, TRE is considered a safe method for those looking to lose weight or improve health. As always, consulting a healthcare provider before making major changes to eating habits is advised. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about Time-Restricted Eating (TRE) for obesity because it introduces a new way of managing calorie intake that differs from traditional methods. Unlike standard treatments like dietary counseling and calorie tracking, TRE involves confining all food consumption to a self-selected 10-hour window each day. This approach may simplify dieting by focusing on when you eat rather than what you eat, potentially making it easier for people to stick with over time. Additionally, TRE might align better with our natural circadian rhythms, possibly enhancing metabolic health and weight loss results.

What evidence suggests that time-restricted eating could be effective for obesity?

Research shows that time-restricted eating (TRE), where eating occurs only during a specific part of the day, can help people with obesity lose weight. Studies have found that those following TRE can lose about 3% to 5% of their body weight over 2 to 12 months. TRE is also linked to a smaller waist size and a better body mass index (BMI), a measure of body fat based on height and weight. By limiting eating times, TRE helps reduce calorie intake, aiding in weight loss. However, some studies suggest that TRE might not always be more effective than other eating habits, so results can vary. In this trial, participants will either follow the TRE approach combined with standard care or receive standard care alone, allowing for a comparison of these approaches. ^{2 3 6 7 8}

Who Is on the Research Team?

Michael J Wilkinson, MD

Principal Investigator

University of California, San Diego

Are You a Good Fit for This Trial?

Adults over 18 with obesity (BMI of 30-50), who eat for more than 14 hours a day and own a smartphone. They must not be on any weight-affecting meds, pregnant, or have various health conditions like heart failure or uncontrolled psychiatric disorders. Those on stable cardiovascular meds can join but can't change doses during the trial.

Inclusion Criteria

I am not changing my heart or cholesterol medication doses during the study.

Baseline eating window ≥ 14 hours/day

My BMI is between 30 and 50.

Exclusion Criteria

Pregnant or breast-feeding women

I have a diagnosed inflammatory or rheumatologic condition.

Active tobacco abuse or illicit drug use or history of treatment for alcohol abuse

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants are randomly assigned to either a control group receiving standard nutritional counseling or an intervention group with time-restricted eating for 12 weeks

12 weeks

Regular visits for counseling and monitoring

Follow-up

Participants are monitored for safety and effectiveness after treatment, including measurements of inflammation, body weight, and body composition

2 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Standard of Care
• Time Restricted Eating

Trial Overview The study is testing if limiting eating to a 10-hour window (Time-Restricted Eating) plus nutritional counseling affects obese adults' health differently compared to just nutritional counseling alone. Participants will follow their assigned eating plan for 12 weeks.

How Is the Trial Designed?

Group I: TRE + SOC Experimental Treatment 1 Intervention

Participants in this arm will receive standard of care nutritional behavioral counseling and will implement a daily, self-selected, 10-hour window within which they must consume all calories. They will also be required to log their caloric intake through the use of a smartphone app

Group II: Standard of Care (SOC) Placebo Group 1 Intervention

Participants will receive standard of care nutritional behavioral counseling and will be required to log their caloric intake through the use of a smartphone app.

Who Is Running the Clinical Trial?

University of California, San Diego

Lead Sponsor

Trials

1,215

Recruited

1,593,000+

Salk Institute for Biological Studies

Collaborator

Trials

23

Recruited

2,200+

Published Research Related to This Trial

Time-restricted eating (TRE) is a feasible and safe intervention for individuals with overweight, obesity, prediabetes, or type 2 diabetes, with high retention rates of 95% for studies under 12 weeks and 89% for those 12 weeks or longer.

Participants generally adhered to TRE well, with median adherence rates of 89% for shorter studies and 81% for longer ones, although individual experiences varied, highlighting the need for support and flexibility in the approach.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Feasibility of time-restricted eating in individuals with overweight, obesity, prediabetes, or type 2 diabetes: A systematic scoping review. Termannsen, AD., Varming, A., van Elst, C., et al.[2023]

In a 12-week study involving 14 adults with obesity, time-restricted feeding (8-hour eating window) led to a significant weight loss of about 2 kg, indicating potential efficacy for weight management.

Despite the weight loss, the study found no significant changes in the diversity or composition of the gut microbiome, suggesting that time-restricted feeding may not impact gut health in terms of microbial diversity.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of time restricted feeding on the gut microbiome in adults with obesity: A pilot study. Gabel, K., Marcell, J., Cares, K., et al.[2022]

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) significantly reduces body weight and fat mass while preserving fat-free mass, based on a meta-analysis of 19 clinical trials.

TRE also improves important metabolic parameters, including lower blood pressure, reduced fasting glucose levels, and better cholesterol profiles, suggesting it could be an effective strategy for managing obesity and metabolic dysfunction.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Beneficial Effects of Time-Restricted Eating on Metabolic Diseases: A Systemic Review and Meta-Analysis. Moon, S., Kang, J., Kim, SH., et al.[2021]

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]

Intermittent fasting (IF) may be an effective weight management strategy for overweight and obese adults, but its evidence base in humans is still limited, with only one published systematic review available.

Current guidelines from the National Institute for Health and Care Excellence (NICE) do not recommend very low calorie diets (VLCD) as a routine treatment for obesity, highlighting concerns about potential side effects and the sustainability of fasting approaches.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Intermittent fasting interventions for the treatment of overweight and obesity in adults aged 18 years and over: a systematic review protocol. Jane, L., Atkinson, G., Jaime, V., et al.[2022]

In a study involving adults with obesity, both 4-hour and 6-hour time-restricted feeding (TRF) regimens led to comparable weight loss of about 3% over 8 weeks, along with improvements in insulin resistance and oxidative stress.

Participants in the TRF groups reduced their daily energy intake by approximately 550 kcal without needing to count calories, suggesting that TRF can be an effective and manageable approach for weight loss and improving cardiometabolic health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of 4- and 6-h Time-Restricted Feeding on Weight and Cardiometabolic Health: A Randomized Controlled Trial in Adults with Obesity. Cienfuegos, S., Gabel, K., Kalam, F., et al.[2022]

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]

Intermittent energy restriction (IER) strategies, such as intermittent fasting and time-restricted feeding, show similar effectiveness in weight loss compared to continuous energy restriction (CER) in adults with obesity, based on a review of randomized trials lasting at least 8 weeks.

Out of 11 studies analyzed, 9 found no significant differences in weight or body fat loss between IER and CER, suggesting that IER can be a viable alternative for obesity treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effectiveness of Intermittent Fasting and Time-Restricted Feeding Compared to Continuous Energy Restriction for Weight Loss. Rynders, CA., Thomas, EA., Zaman, A., 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]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10672223/

Time-Restricted Eating and Its Metabolic Benefits - PMC In a randomized controlled trial, patients following eTRE (8 h window) lost more weight than patients eating during a window of at least 12 h [ ...

2. 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 ...

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC6836017/

Effectiveness of Intermittent Fasting and Time-Restricted ... Eating “around the clock” has been suggested to have detrimental effects on health and body weight, leading to a desire to study time ...

4. sciencedirect.com sciencedirect.com/science/article/pii/S2589004224002219

Time-restricted eating improves health because of energy ... The results showed that TRE led to modest weight loss, lower waist circumference and energy deficits. TRE also improved body mass index, fat ...

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

Effects of Time-Restricted Eating on Weight Loss and Other ... Time-restricted eating, in the absence of other interventions, is not more effective in weight loss than eating throughout the day.

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11221496/

Time-restricted eating: Watching the clock to treat obesity Time-restricted eating (TRE) has become a popular strategy to treat obesity. TRE involves confining the eating window to 4–10 h per day and fasting for the ...

7. academic.oup.com academic.oup.com/edrv/article/43/2/405/6371193

Time-restricted Eating for the Prevention and Management of ... Pilot human intervention studies have reported promising results in reducing the risk for obesity, diabetes, and cardiovascular diseases. Epidemiological ...

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

The Effects of Time-Restricted Eating on Fat Loss in Adults ... Conclusions: This work provides moderate to high evidence that TRE is a promising dietary strategy for fat loss. Although it may potentially reduce lean mass ...