48 Participants Needed

Light Exposure + Meal Timing for Circadian Rhythm Management

(LipidPRC Trial)

SA
LK
Overseen ByLeilah K Grant, PhD
Age: 18 - 65
Sex: Any
Trial Phase: Academic
Sponsor: Brigham and Women's Hospital
No Placebo GroupAll trial participants will receive the active study treatment (no placebo)

Trial Summary

What is the purpose of this trial?

The aim of this study is to determine the principal time cue (light or meals) for resetting circadian rhythms in melatonin and metabolic outcomes.

Do I have to stop taking my current medications for the trial?

Yes, you will need to refrain from taking medications and supplements during the study, except for birth control.

What data supports the effectiveness of the treatment Light Exposure + Meal Timing for Circadian Rhythm Management?

Research suggests that time-restricted eating (TRE), which involves eating within a specific time window, can help with weight loss, improve glucose tolerance, and enhance overall metabolic health. Additionally, meal timing and light exposure can synchronize biological clocks, potentially improving sleep patterns and metabolic functions.12345

Is time-restricted eating safe for humans?

Research suggests that time-restricted eating, where food is consumed within a specific time window each day, is generally safe for humans. Studies have shown that it can be safely practiced by adults, including those with obesity, without causing adverse effects.34678

How does the treatment of light exposure and meal timing for circadian rhythm management differ from other treatments?

This treatment is unique because it combines light exposure and meal timing to align the body's internal clock with natural day-night cycles, potentially improving metabolic health and reducing the risk of chronic diseases. Unlike traditional treatments that may focus on medication or diet changes alone, this approach uses the timing of meals and light as natural cues to synchronize the body's circadian rhythms.345910

Eligibility Criteria

This trial is for healthy individuals aged 18-30 who don't smoke, use drugs, or have sleep disorders. They must maintain an 8-hour sleep schedule and avoid caffeine, alcohol, and most medications during the study. Participants should have a BMI between >18 and <30 kg/m2.

Inclusion Criteria

Body Mass Index of >18 or <30 kg/m2
I am between 18 and 30 years old.
Non-smoking for at least 6 months
See 3 more

Exclusion Criteria

Any other reason as determine by the Principal Investigator
Transmeridian travel (2 or more time zones) in the past 3 months
I have a recent or ongoing health issue.
See 8 more

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants undergo interventions involving 6.5-hour bright light exposure and time-restricted eating to study circadian rhythm shifts

6.5 hours per session
Daily sessions

Follow-up

Participants are monitored for changes in melatonin and lipid levels after interventions

24 hours

Treatment Details

Interventions

  • 12-h meal window
  • Bright Light
  • Dim light
  • Time-restricted eating
Trial OverviewThe study tests whether light exposure or meal timing has a greater effect on resetting circadian rhythms related to melatonin production and metabolism. It involves time-restricted eating within a 12-hour window and exposure to bright or dim light.
Participant Groups
3Treatment groups
Experimental Treatment
Placebo Group
Group I: Time-restricted eatingExperimental Treatment2 Interventions
Participants will consume 4 identical meals, as in the other groups, except that the meal window will be restricted to 6.5 hours instead of 12 hours (meals at 4.75, 6.9, 9.1, 11.25 hours after waking) centered within the 16-hour wake episode. Participants will remain in dim light (\<3 lux) throughout the 16-hour wake episode.
Group II: Bright lightExperimental Treatment2 Interventions
Participants will receive a 6.5-hour 10,000 lux light pulse (4100K fluorescent light) centered within the 16-hour wake episode (start 4.75 hour after wake and end 11.25 hour after wake). Participants will receive 4 identical meals (equal calories and macronutrient content), over a 12-hour interval (meals at 2, 6, 10, and 14 hours after waking) centered within the 16-hour wake episode.
Group III: ControlPlacebo Group2 Interventions
Participants will receive 4 identical meals (equal calories and macronutrient content), over a 12-hour interval (meals at 2, 6, 10, and 14 hours after waking) centered within the 16-hour wake episode. Participants will remain in dim light (\<3 lux) throughout the 16-hour wake episode.

Find a Clinic Near You

Who Is Running the Clinical Trial?

Brigham and Women's Hospital

Lead Sponsor

Trials
1,694
Recruited
14,790,000+

Findings from Research

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.
Daily pattern of energy distribution and weight loss.Raynor, HA., Li, F., Cardoso, C.[2019]
Constant light exposure (LL) significantly disrupts circadian rhythms in metabolic processes, particularly affecting the liver more severely than white adipose tissue (WAT), leading to increased body weight despite similar food intake.
Time-restricted feeding during LL can partially restore circadian rhythms in both liver and WAT, suggesting a potential strategy to mitigate the negative effects of constant light on metabolism.
Peripheral circadian rhythms in the liver and white adipose tissue of mice are attenuated by constant light and restored by time-restricted feeding.Yamamuro, D., Takahashi, M., Nagashima, S., et al.[2020]
Time-restricted eating (TRE) has shown promising therapeutic effects in rodent studies, particularly in relation to body weight and metabolic health, but results in humans are inconsistent due to varying study designs and populations.
This review highlights the need for more standardized research on TRE in humans to better understand its effects and interactions with circadian biology, as well as to identify gaps in current knowledge for future studies.
Complex physiology and clinical implications of time-restricted eating.Petersen, MC., Gallop, MR., Flores Ramos, S., et al.[2023]

References

Daily pattern of energy distribution and weight loss. [2019]
Peripheral circadian rhythms in the liver and white adipose tissue of mice are attenuated by constant light and restored by time-restricted feeding. [2020]
Complex physiology and clinical implications of time-restricted eating. [2023]
Time-Restricted Eating: Benefits, Mechanisms, and Challenges in Translation. [2021]
Metabolic and reward feeding synchronises the rhythmic brain. [2014]
Safety of 8-h time restricted feeding in adults with obesity. [2019]
The feasibility and preliminary efficacy of early time-restricted eating on diet quality in college students: A randomized study. [2022]
Associations between the timing of eating and weight-loss in calorically restricted healthy adults: Findings from the CALERIE study. [2022]
Will Delaying Breakfast Mitigate the Metabolic Health Benefits of Time-Restricted Eating? [2021]
Time-restricted eating for chronodisruption-related chronic diseases. [2023]