Fear, Gastrointestinal Distress, and Interoception: Physiological and Psychological Mechanisms in Eating Disorders

Study Overview
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Brief Summary
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The proposed study tests fear, gut peptide response, and perceptions of fullness as causes of gastrointestinal distress and eating disorder maintenance.

Official Title
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Fear, Gastrointestinal Distress, and Interoception: Physiological and Psychological Mechanisms in Eating Disorders

Conditions
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Feeding and Eating Disorders

Intervention / Treatment
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* Other: Test meal description changed


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: female DSM-5 eating disorder score 16 or higher on the Clinical Impairment Assessment experience nausea or stomachache after eating at least sometimes 18 to 40 years old body mass index between 18.5 and 26.5 kg/m2 Exclusion Criteria: medical conditions affect appetite or weight Recent pregnancy or current breastfeeding Dairy, strawberry or honey food allergy Specific phobia, blood-injection-injury type

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: High Fat Yogurt - Low Fat Yogurt<br>Participants will eat yogurt described as 'high fat' at Study Visit 2 and yogurt described as 'low fat' at Study Visit 3. | Other: Test meal description changed<br>* Using a within-subjects crossover design, on two separate mornings participants will eat yogurt described as 'high fat' and 'low fat.' In actuality, the meals will not differ.<br>|
| Other: Low Fat Yogurt - High Fat Yogurt<br>Participants will eat yogurt described as 'low fat' at Study Visit 2 and yogurt described as 'high fat' at Study Visit 3. | Other: Test meal description changed<br>* Using a within-subjects crossover design, on two separate mornings participants will eat yogurt described as 'high fat' and 'low fat.' In actuality, the meals will not differ.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Subjective rating of fear | Area under the curve with respect to increase (AUCi) from the 10 minutes period prior to the meal until immediately after the meal will be used to characterize changes in Visual Analogue Scale ratings of momentary fear ranging from Not at All to Extreme. Subjective fear immediately before the meal will be used in mediation models. | -10 minutes, 0 minutes (immediately after the intervention), and 10 minutes post-intervention | 
| Skin conductance | Skin conductance data will be collected using a Biopac Bionomadix EDA System. Difference scores will be computed for both test meals by comparing mean skin conductance level (expressed in log units) over the 10 minute meal period to the 10 minute period before the meal. | -10 minutes, 0 minutes (immediately after the intervention), and 10 minutes post-intervention | 
| Gastrointestinal distress | Gastrointestinal distress will be the averaged visual analogue scale ratings of Nausea and Stomach Ache ranging from Not At All to Extreme. Area under the curve with respect to increase (AUCi) from the 10 minutes period prior to the meal until immediately after the meal will be used to characterize changes gastrointestinal distress. The 20-minute assessment of gastrointestinal distress will be used for the hypothesis testing mediators of the relationship between fear and gastrointestinal distress and the 30 minute assessment will be used for the exploratory serial multiple mediation model. | -10 minutes, 0 minutes (immediately after the intervention), 10 minutes, 20 minutes, 30 minutes, 60 minutes and 90 minutes post-intervention | 
| Cholecystokinin response | Blood will be drawn repeatedly. Cholecystokinin (CCK) values in plasma will be quantified using a commercially available enzyme immunoassay. Area under the curve with respect to increase (AUCi) will be calculated for all time periods to compare between test meal instructions. CCK values 10 minutes after the intervention will be used in mediation models. | 0 minutes (immediately after the intervention), 10 minutes, 20 minutes, 30 minutes, 60 minutes and 90 minutes post-intervention | 
| Peptide YY response | Blood will be drawn repeatedly. PYY3-36 values in plasma will be quantified using a commercially available enzyme immunoassay. Area under the curve with respect to increase (AUCi) will be calculated for all time periods to compare between test meal instructions. PYY values 10 minutes after the intervention will be used in mediation models. | 0 minutes (immediately after the intervention), 10 minutes, 20 minutes, 30 minutes, 60 minutes and 90 minutes post-intervention | 
| Subjective rating of fullness | Fullness will be the averaged visual analogue scale ratings of full and satiated(satisfied) ranging from Not At All to Extreme. Area under the curve with respect to increase (AUCi) will be used to characterize changes in fullness from immediately before the test meal to 90 minutes after. The 10-minute assessment of fullness will be used in testing fullness as a mediator of the relationship between fear and gastrointestinal distress and the 20 minute assessment will be used for the exploratory serial mediation model. | 0 minutes (immediately after the intervention), 10 minutes, 20 minutes, 30 minutes, 60 minutes and 90 minutes post-intervention | 
| Urges to restrict food intake | Visual analogue scales will assess momentary urge to restrict from Not At All (0) to Extreme (100). The 60 minute assessment will be used for the exploratory serial mediation model. | 60 minutes post-intervention |