Food Timing for Eating Habits

Overseen By Ioannis Lempesis, MD, PhD, PhD

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: Brigham and Women's Hospital

Disqualifiers: Smokers, Drug dependency, Pregnant

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

Compensation: Varies

Number of Visits: 2

Duration: 24 hours per protocol

48 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how meal timing affects metabolic health. Participants will follow different eating schedules, either during the day or night, with two types of diets. The goal is to determine if eating at specific times can influence health markers in individuals without health issues. It suits healthy individuals who do not smoke or use tobacco products and have a BMI (body mass index) between 18.5 and 29.9. As an unphased trial, this study provides a unique opportunity to contribute to the scientific understanding of meal timing and health.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

What prior data suggests that these dietary protocols are safe for participants?

Research has shown that time-restricted eating, which involves eating only during a set number of hours each day, is generally safe. Studies have found that eating within a 4-10 hour window does not negatively affect diet quality. In fact, it may aid in weight loss and improve heart health.

For night shift workers, research suggests that customized diets can help manage health risks associated with night work, such as heart disease. Although night shift work is linked to certain health issues, adjusting meal timing and content can be beneficial.

Overall, eating schedules for both day and night are well-tolerated, with no major safety concerns reported in the studies. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the "Food Timing for Eating Habits" trial because it explores how the timing of meals affects eating habits, particularly for people on different work shifts. Unlike traditional studies focusing solely on what we eat, this trial investigates when we eat, which could reveal new insights into managing eating habits and possibly improving health outcomes. By comparing day and night shift meal timings and orders, researchers hope to understand better how these factors influence metabolism and overall health, potentially leading to new guidelines for meal scheduling that enhance well-being.

What evidence suggests that this trial's dietary protocols could be effective for metabolic health?

This trial will compare different dietary protocols for day and night shift workers. Research has shown that time-restricted eating (TRE), where meals are consumed within a specific time each day, can improve metabolic health. Studies indicate that TRE can aid in weight loss and lower heart disease risks when meals are eaten during daylight hours. For night shift workers, meal timing can also impact health. Approaches like intermittent fasting have shown promise for weight loss and managing health issues related to night work. Adjusting meal times might help reduce health problems for night shift workers. Overall, research suggests that meal timing may be just as important as meal content. ^{2 6 7 8 9}

Who Is on the Research Team?

Frank Scheer, PhD

Principal Investigator

Brigham and Women's Hospital

Are You a Good Fit for This Trial?

This trial is for healthy individuals with a BMI between 25.0-34.9, without any acute or chronic medical and psychiatric conditions. It's designed to explore if when you eat affects your risk of developing diabetes.

Inclusion Criteria

BMI 25.0-34.9 kg/m2

I am healthy with no ongoing medical or mental health issues.

Exclusion Criteria

Individuals with drug or alcohol dependency

Smokers, current tobacco or e-cigarette users

Pregnant individuals

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Inpatient Stay

Participants complete 2 inpatient stays and are provided with test meals

2 stays

2 inpatient visits

Treatment

Participants undergo different food timing protocols to assess metabolic health

24 hours per protocol

Frequent blood draws during each protocol

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Day shift protocol - Diet order A-B
• Day shift protocol - Diet order B-A
• Night shift protocol - Diet order A-B
• Night shift protocol - Diet order B-A

Trial Overview Participants will follow different eating schedules while staying at the clinic twice. They'll receive test meals and undergo frequent blood tests to see how meal timing might influence their body's metabolism.

How Is the Trial Designed?

Group I: Night shift protocol with diet B Experimental Treatment 2 Interventions

Night shift protocol with diet B condition. Since this is a single-blind study, the details of the meal conditions cannot be released during the recruitment stage but will be made public once enrollment closes.

Group II: Night shift protocol with diet A Experimental Treatment 2 Interventions

Night shift protocol with diet A condition. Since this is a single-blind study, the details of the meal conditions cannot be released during the recruitment stage but will be made public once enrollment closes.

Group III: Day shift protocol with diet B Experimental Treatment 2 Interventions

Day shift protocol with diet B condition. Since this is a single-blind study, the details of the meal conditions cannot be released during the recruitment stage but will be made public once enrollment closes.

Group IV: Day shift protocol with diet A Experimental Treatment 2 Interventions

Day shift protocol with diet A condition. Since this is a single-blind study, the details of the meal conditions cannot be released during the recruitment stage but will be made public once enrollment closes.

Who Is Running the Clinical Trial?

Brigham and Women's Hospital

Lead Sponsor

Trials

1,694

Recruited

14,790,000+

Published Research Related to This Trial

A study using a mobile app to track eating patterns in healthy adults revealed that most people eat erratically throughout the day, with a significant portion of calories consumed late in the evening, leading to a daily eating duration exceeding 14.75 hours for many participants.

Overweight individuals who reduced their eating window to 10-11 hours daily for 16 weeks, using a visual tool to track their intake, experienced weight loss, increased energy levels, and improved sleep, with these benefits lasting for a year.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A Smartphone App Reveals Erratic Diurnal Eating Patterns in Humans that Can Be Modulated for Health Benefits. Gill, S., Panda, S.[2022]

Late-shift hospital workers experienced a significantly greater mean weight gain of 4.3 kg compared to 0.9 kg in day-shift workers, suggesting a link between shift work and weight gain.

Factors contributing to this weight gain in late-shift workers included a trend of increased food intake, fewer meals consumed, and later meal times, along with reported decreases in exercise and increased napping during the work week.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Work-shift period and weight change. Geliebter, A., Gluck, ME., Tanowitz, M., et al.[2019]

The SWIFt study is a pioneering randomized controlled trial designed to evaluate three different weight-loss interventions specifically for night-shift workers, addressing their unique challenges related to obesity.

This mixed-methods evaluation will not only assess the effectiveness of these interventions but also explore individual and environmental factors that influence weight-loss outcomes, providing insights for future tailored dietary programs.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Evaluation of the "Shifting Weight using Intermittent Fasting in night-shift workers" weight loss interventions: a mixed-methods protocol. Davis, C., Bonham, MP., Kleve, S., et al.[2023]

Rotating shift workers consume significantly more calories (about 264 kJ more) compared to those on regular daytime schedules, indicating a potential metabolic risk associated with irregular work hours.

The dietary patterns of rotating shift workers differ from day workers, characterized by irregular meal times, increased snacking, and a higher intake of discretionary foods, which may contribute to their higher energy intake.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dietary Patterns under the Influence of Rotational Shift Work Schedules: A Systematic Review and Meta-Analysis. Clark, AB., Coates, AM., Davidson, ZE., et al.[2023]

In a study of 50 middle-aged health workers in Chile, shift workers had a lower carbohydrate intake and higher protein intake compared to day workers, despite similar total energy consumption.

Shift workers exhibited decreased diet quality and irregular eating patterns, highlighting the importance of meal timing and diet quality for future interventions targeting this group.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Impact of Shift Work on the Eating Pattern, Physical Activity and Daytime Sleepiness Among Chilean Healthcare Workers. Farías, R., Sepúlveda, A., Chamorro, R.[2020]

A study of 66 garbage collectors in Florianopolis, Brazil, revealed that while daily energy intake was similar across morning, afternoon, and night shifts, the types of foods consumed varied significantly based on the shift, affecting nutrient intake.

Despite high energy expenditure, especially among morning shift workers, the overall dietary patterns and circadian rhythms of food intake highlight the importance of analyzing food choices in relation to work shifts, as total daily intake alone may not capture these differences.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Food intake and circadian rhythms in shift workers with a high workload. de Assis, MA., Kupek, E., Nahas, MV., et al.[2019]

The integrated chrono-nutrition weight reduction program, involving 91 overweight/obese participants over 12 weeks, successfully improved meal timing and reduced late-night eating, indicating its efficacy in modifying dietary habits for weight management.

Evening chronotypes experienced significant improvements in sleep duration and reduced social jetlag, suggesting that the program not only aids in weight reduction but also enhances overall sleep quality.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Development and Evaluation of Integrated Chrono-Nutrition Weight Reduction Program among Overweight/Obese with Morning and Evening Chronotypes. Mazri, FH., Manaf, ZA., Shahar, S., et al.[2023]

A review of five studies involving 670 night shift workers found that dietary interventions did not lead to weight loss over six or twelve months, but did result in a decrease in LDL-cholesterol levels after six months.

The timing of meals significantly affected metabolic responses, with triglycerides peaking after evening meals and glucose and insulin levels peaking later, indicating that meal timing may play a crucial role in managing cardiometabolic health for night shift workers.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dietary Interventions for Night Shift Workers: A Literature Review. Phoi, YY., Keogh, JB.[2020]

In a 12-week study involving 91 overweight/obese non-shift workers, those who achieved a satisfactory weight loss (≥3% body weight) had a significantly higher intake of protein earlier in the day and reduced fat intake later in the day, indicating that timing and composition of meals are crucial for weight loss success.

Participants with satisfactory weight loss also had earlier last meal times and shorter eating windows, along with a notable reduction in night eating syndrome scores, suggesting that chrono-nutrition practices can effectively support weight reduction efforts.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Improvement in chrono-nutrition is associated with robust weight loss outcomes: An extension of the feasibility study. Mazri, FH., Manaf, ZA., Shahar, S., et al.[2023]

In a study of seven healthy adult men over eight weeks, it was found that shift-work did not significantly alter overall caloric intake or the percentage of calories from protein, despite changes in carbohydrate eating patterns, such as increased nibbling during night shifts.

The timing of main meals remained consistent across shifts, but this regularity had little effect on aligning meal times with the body's circadian rhythms, suggesting that meal timing is not an effective strategy for synchronizing eating with biological clocks.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Circadian and ultradian rhythms in the feeding behaviour and nutrient intakes of oil refinery operators with shift-work every 3--4 days. Reinberg, A., Migraine, C., Apfelbaum, M., et al.[2004]

A study involving 608 participants found that most people typically eat within a 10 to 14-hour window on both workdays and free days, indicating a common pattern of energy intake.

The likelihood of adopting time-restricted feeding (TRF) decreases as the proposed feeding window restriction increases, with key factors influencing this decision being cost, time availability, and perceived health benefits.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Identification of factors influencing motivation to undertake time-restricted feeding in humans. Jefcoate, PW., Robertson, MD., Ogden, J., et al.[2021]

In a study of 84 workers divided into three groups, there was no significant difference in daily caloric intake among shift workers on different rotating schedules and day workers.

However, shift workers who gained weight more quickly tended to have higher caloric intake on their days off and after evening meals, suggesting that eating patterns may influence weight gain in shift workers.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Caloric intake and weight gain according to the shift schedule of shift workers]. Romon, M., Beuscart, R., Frimat, P., et al.[2008]

In an 8-week pilot study with 8 participants, consuming a larger portion of daily calories in the morning led to significantly greater weight loss and improved regularity of sleep patterns compared to eating more calories in the evening.

This research suggests that timing of energy intake may enhance biological circadian rhythms, but further studies with larger groups and more comprehensive methods are needed to fully understand its health impacts.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Daily pattern of energy distribution and weight loss. Raynor, HA., Li, F., Cardoso, C.[2019]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7262456/

Time-Restricted Eating: Benefits, Mechanisms, and ... Time-restricted eating (TRE) is a dietary approach that consolidates all calorie intake to 6- to 10-h periods during the active phase of the day.

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

Time-restricted eating improves health because of energy ... The data indicated that TRE was effective in weight loss and metabolic health, and these benefits were due to a joint effect of energy ...

3. nature.com nature.com/articles/s41467-025-57846-y

Daytime eating during simulated night work mitigates ... We found evidence for an increase in cardiovascular risk factors after simulated night work with nighttime and daytime eating, whereas a Daytime ...

4. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11338815/

Time-restricted eating, the clock ticking behind the scenes Caloric restriction (CR) diets and intermittent fasting (IF) interventions have emerged as effective approaches to improving cardiometabolic ...

5. jamanetwork.com jamanetwork.com/journals/jamanetworkopen/fullarticle/2835598

Time-Restricted Eating, Sleep, and Quality of Life The question of whether the timing and duration of an individual's daily eating window can influence sleep quality and psychological well-being ...

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC5388543/

Fasting, circadian rhythms, and time restricted feeding in ... If daily, alternate daily, or periodic fasting can promote healthy lifespan by exerting pleiotropic effects, restoring a fasting period or switching to a diet ...

7. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11175017/

Effects of Early and Late Time-Restricted Feeding on ... Time-restricted feeding (TRF) has been shown to reduce body weight (BW) and/or improve cardiovascular biomarkers.

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

Time-restricted eating: Watching the clock to treat obesity These preliminary studies show that limiting the eating window to 4–10 h per day does not negatively impact diet quality, but more research is ...

9. 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 ...