Circadian Control of Human Circulating Endocannabinoid Levels

Study Overview
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Brief Summary
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The purpose of this study is to examine how the timing of eating changes how the body makes and uses energy (metabolism). This study will also examine how fat cells respond to insulin (a hormone that controls blood sugar levels).

Detailed Description
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The timing of food intake and caloric distribution across the 24hr day are emerging as contributing factors to weight gain. The idea that not only what you eat, but when you eat can contribute to weight gain has garnered interest from both the scientific community and the public. In fact, the distribution of caloric intake over the 24hr day has been recently recognized as a potential source of circadian misalignment which can result in adverse health outcomes, including overeating, impaired glucose tolerance and insulin sensitivity. Moreover, reward driven eating (eating for the pleasurable aspect instead of energy need) generally results in caloric intake well in excess of energy requirements and is recognized as a major culprit in the epidemic of obesity. The endocannabinoid (eCB) system is involved in both homeostatic processes (energy need only) that govern food intake, and has been shown to play a key role in reward eating. Thus, the role of circadian organization of the eCB system and how misalignment may contribute to overeating, overweight, obesity, and diabetes is the main focus of this study. The overall goal is to determine whether the timing of food intake is a major determinant of the 24 hour variation in eCB activity that in turn affects hunger and appetite, glucose metabolism, and insulin sensitivity. This study will focus on overweight individuals who are at high risk of obesity but are still on a trajectory that can potentially be reversed by lifestyle changes. Following a careful assessment of the subject's habitual sleep and meal timing and caloric distribution under real life conditions, a short laboratory study will determine whether participants who consume more of their daily calories later in the day (later dietary chronotype) display delays in the eCB rhythm and lower insulin sensitivity. During a 6-day in patient intervention, combining laboratory and ambulatory procedures, study procedures will assess the effect of experimentally changing caloric distribution across the day, advancing versus delaying the dietary chronotype. The outcome measures will be the timing of the daily peak of the eCB rhythm and insulin sensitivity. This study will also measure the potential durability of the intervention on subsequent habitual behavior under real life conditions, in that how long does one maintain the feeding in lab imposed feeding schedule and does that schedule effect subsequent behavior and/or weight. Identification of circadian misalignment of the eCB system as a mediator of increased food intake and reduced insulin sensitivity may help develop novel preventive strategies.

Official Title
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Circadian Control of Human Circulating Endocannabinoid Levels

Conditions
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Obesity

Intervention / Treatment
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* Behavioral: Early Total Caloric Intake
* Behavioral: Late Total Caloric Intake


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: self-report sleeping between 7-hrs/night and 9-hrs/night, between 22:00 and 08:00 self-report having gained at least 3lbs in the last year Exclusion Criteria: no previously diagnosed sleep disorders (including obstructive sleep apnea (OSA)) no existing diagnosis of prediabetes or diabetes no history of endocrine dysfunction no history of psychiatric, cardiovascular, or eating disorders must not have a gastro-intestinal disease that requires dietary adjustment currently taking no medications (including birth control) drug and nicotine use, habitual alcohol use of more than 2 drinks per day, and caffeine intake of more than 300 mg per day anyone who has participated in medically managed weight loss program within the past year, anyone who has undergone bariatric surgery, must not have dietary restrictions must not work night shifts or crossed any time zones in the month prior to the study.

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Early Total Caloric Intake<br>The Early Total Caloric Intake study group will consume the majority of their daily calories during breakfast. | Behavioral: Early Total Caloric Intake<br>* Provide subjects a regimented amount of calories at each meal.<br>|
| Active Comparator: Late Total Caloric Intake<br>The Late Total Caloric Intake study group will consume the majority of their daily calories during dinner. | Behavioral: Late Total Caloric Intake<br>* Provide subjects a regimented amount of calories at each meal.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in timing of peak of endocannabinoid rhythm | The change in the timing (hours) of the peak of the endocannabinoid rhythm from baseline to 37 days after the intervention will be measured. | Day 37 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Weight | The change in weight (kilograms) from baseline to 37 days after intervention will be measured. | Day 37 |