Sleep and Food-based Decision Making

Study Overview
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Brief Summary
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This study administers two prescribed sleep levels, each lasting one week, that participants will complete in their at-home environment. One week is a well-rested (8-9 hrs/night attempted sleep) and another is a sleep-restricted (5-6 hrs/night attempted sleep) condition. In between these two conditions is an ad lib sleep week. At the end of each treatment week, the participants come to a laboratory session to go through a series of decision making tasks. Participants also track dietary intake through the 3-week protocol using the ASA24 website. This study was fully preregistered on the open science framework (OSF) has has registration DOI at https://doi.org/10.17605/OSF.IO/NSPRK

Detailed Description
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THE PRELIMINARY SCREENING SURVEY: This short demographic, sleep, and mood survey is administered at least twice a year by the investigator (Dickinson) on random subsets of students at his institution. This database survey had been ongoing for several years and has been approved under separate human subjects approval process, and has been used by the investigator (Dickinson) to recruit for a variety of sleep and decision research studies over the years. This short survey provides sufficient information for the investigators to screen out individuals who self-report a sleep disorder, who are not within the 18-40 year old target age range for this study, who are at significant risk of major depressive or anxiety disorder (assessed using validated short-instruments). Viable participants who meet the inclusion criterion (usually, only about 2/3 of those who complete the survey) are randomly assigned to either the control condition or a particular ordering of the treatment condition (SR-WR or WR-SR), ex ante. Afterwards, these individuals are invited to participate in the experiment via email. (note, participants are NOT allowed to opt into a condition or treatment ordering to which they were not randomly assigned) THE SLEEP PROTOCOL: The basic sleep protocol will involve recruitment of a total of 130 participants. Participants are randomly assigned to the control condition (N=30) or the treatment condition (n=100). The investigators anticipate some attrition such that n>130 will be enrolled in the study to ultimately obtain n=130 participants who will have successfully completed the entire protocol. Both conditions involve 3-weeks of at-home prescribed sleep levels for the participants. For the Control participants, week 1 prescribes 8-9 hours of attempted sleep per night for the 7 nights of that week (refer to this as a well-rested [WR] week). Week 3 for Control participants will be another prescribed WR week. Treatment participants will be prescribed a WR week in week 1 or week 3 and a sleep-restricted (SR) week (5-6 hrs/night attempted sleep) then in week 3 or week 1. That is, treatment participants will be administered the treatment conditions either in SR-WR or in WR-SR order (counterbalanced across participants). For all participants (control and treatment), week 2 is an ad lib sleep week to wash out the treatment effects of week 1 before commencing the week 3 prescribed sleep level. All participants will complete basic sleep diary records for the entire 3 weeks and will wear a validated sleep-tracking actigraphy device for the duration of the period. Objectively measured actigraphy sleep data will be scored using validated protocols. The idea of the 3-week sleep protocol is to obtain within-participants measures of decision-making that will be assessed at the end of weeks 1 and 3 (the treatment weeks) with the participant in an experimentally manipulated state of well-restedness or chronic partial sleep restriction (similar to recommended WR levels and levels of SR common in many adult populations). ADDITIONAL STUDY ELEMENTS In addition to decision making that will be assessed at the end of weeks 1 and 3 of the protocol (i.e., after each experimentally prescribed sleep week), participants will also complete daily food recalls of their dietary intake over the course of the 3-week protocol, as well as a short form of the International Physical Activity Questionnaire (IPAQ) and validated measures of cognitive and sleep function at the end of each week of the protocol. The IPAQ, as well as cognitive and sleep function assessments, will be administered online prior to the in-lab decision session at the end of each week (all three weeks). The daily food recalls will be completed online using the Automated Self-Administered 24-hour dietary assessment tool (ASA24).

Official Title
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Insufficient Sleep and Dietary Choices: An Ecologically Valid Examination of the Decision Foundations of Eating Behaviors When Sleep Restricted

Conditions
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Sleep

Intervention / Treatment
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* Other: Sleep levels


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18-40 years of age Exclusion Criteria: at risk of major depressive or anxiety disorder (from validated screener), self-reported or suspected sleep disorder, extreme diurnal preference type (from validated screener)

Ages Eligible for Study
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Minimum Age: 18 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: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Treatment group<br>Participants randomly assigned to the treatment group arm experience both a well-rested and sleep-restricted week during the study | Other: Sleep levels<br>* Sleep levels are what the experimenter prescribes to participants in the study.<br>|
| Placebo Comparator: Control group<br>Participants randomly assigned to the treatment group arm experience two well-rested weeks during the study (and they still have an ad lib sleep week in between the two well-rested weeks) | Other: Sleep levels<br>* Sleep levels are what the experimenter prescribes to participants in the study.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Food-Image based go no-go task: | This task is validated in the literature and available in Inquisit programmed form. It assesses inhibitory control in food related image selection (go) or non-selection (no-go) as compared to non-food related images | 3 weeks | 
| Food-image based Approach Avoidance task | This is a validated task available in Inquisit programmed form and it assess automatic processing to compare one's tendency to approach (pull image towards oneself on computer screen) or avoid (push image away from oneself on computer screen) images reflecting healthier versus less healthy foods | 3 weeks | 
| Food Choice Task | This task gives participants a short time span (e.g., 10 seconds) to select a set of food images to place in one's onscreen cart. Images includes healthier and unhealthy items. | 3 weeks | 
| Food preference (ratings) task | This just asks individual to report on a 0-100 scale how much they like various foods based on a displayed image of each (with higher numbers meaning the participant likes the item more) | 3 weeks | 
| Delay-discounting monetary choice task | This validated task asks one's preference of monetary amounts received today versus larger amounts received at some future point (e.g., 7 days, or 85 days later). Actual choices are paid out for a randomly selected subset of participants on a randomly selected trial (different trials vary the size of the monetary difference and the number of delays for the delayed reward). | 3 weeks | 
| Food information based confirmation bias task | This task assesses one's tendency to consider arguments regarding the healthiness or tastiness of food as more or less strong based on whether that participants dominant food ideology favors the consideration of healthiness or tastiness of food. The investigators have pilot tested and published a paper on this task. | 3 weeks | 
| Snack/drink auction task | In this task, participants are given a snack and a beverage as part of a decision session and allowed to bid on how much they would pay (or need to be paid) to exchange their snack or drink for a different snack or drink. Various combinations of snack auctions and drink auctions are considered in order to compare willingness to pay for healthier or less healthy snacks or drinks) | 3 weeks | 
| Story retelling task | This validated task presents participants with a short story that they are asked to retell so that we can assess preservation of key story details. | 3 weeks | 
| Dietary intakes | These data are gathered from daily dietary intakes input by participants on the ASA24 dietary recall website, which allows for separation of outcomes by various macronutrients. | 3 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Psychomotor vigilance task | This validated task assesses reaction time | 3 weeks | 
| Karolinska sleepiness scale | This validated task assess subjective sleepiness (in the moment). This is assess at Baseline and at the decision sessions that occur during the protocol. | 3 weeks | 
| Objective Sleep duration | These data are collected from research-grade actigraphy devices worn by the participant. | 3 weeks |