Eating Behaviors in Shift Workers

Study Overview
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Brief Summary
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This study will compare eating behaviors and measures of hunger and fullness between day and night workers in order to better understand why night workers are at increased risk for obesity and related diseases.

Official Title
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The Interaction of Shift Work and Food Environment on Eating Behaviors and Appetite

Conditions
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Shift Work Type Circadian Rhythm Sleep Disorder, Eating Behavior

Intervention / Treatment
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* Behavioral: Portion size


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Work   8-hour shifts during day or night on 3 or more consecutive days of the week BMI 19-35 kg/m^2 Age 20-55 years of age Metabolically healthy Weight stable over previous 3 months Lives in New York City area Exclusion Criteria: Pregnant or less than 1 year postpartum at time of study Smoking History of drug or alcohol abuse Rotating shift work Habitual sleep duration of more than 6 hour per night Obstructive sleep apnea Transmeridian travel Type 2 diabetes Cardiovascular disease Hypertension Participation in diet or weight loss program in the 3 months prior to enrollment Psychiatric or sleep disorder Food allergies or intolerances Dislike of or unwillingness to eat test foods

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 55 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: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: This is a mixed design with two participant groups (between-subject), day and night workers, each being exposed to 4 levels of food portion size (within-subjects factor)
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Day worker<br>Men and women who work only day shift for at least 3 consecutive days of the week | Behavioral: Portion size<br>* The amount of food served (g) at the first two meals of each day. These amounts will vary across 4 weeks.<br>|
| Active Comparator: Night worker<br>Men and women who work only night shift for at least 3 consecutive days of the week | Behavioral: Portion size<br>* The amount of food served (g) at the first two meals of each day. These amounts will vary across 4 weeks.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Food intake | Food by weight (g) in response to variations in portion served | 24-hours intake period | 
| Energy intake | Food by energy (kcal) in response to variations in portion served | 24-hours intake period | 
| Energy density consumed | Energy density consumed (kcal/g) in response to variations in portion served | 24-hours intake period | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Appetite-regulating hormones | Appetite-regulating hormones, including Glucagon-like-peptide 1 (GLP-1) and ghrelin will be analyzed from plasma from whole blood samples collected while fasted and at 30, 60, 90, and 120 min postprandial. Area under the curve of plasma concentrations will be calculated for each individual appetite-regulating hormone | 2-hours measurement period | 
| Hunger and fullness | Subjective measures related to hunger, fullness, and prospective consumption will be measured before and after meals via visual analog scales. The range of scores are 0 mm to 100 mm, with higher scores indicating greater feelings of the corresponding measure (e.g. greater hunger). Post-meal measures, adjusted for the corresponding pre-meal measure, will be analyzed as individual outcomes. Area under the curve will also be calculated for each measure. | 24-hours measurement period |