Combined Effects of Variety and Portion Size on Meal Intake of Women

Study Overview
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Brief Summary
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The primary purpose of this study is to investigate the combined effects of meal variety and portion size on food intake at a meal. The study will also investigate relationships with eating microstructure such as eating rate and bite size. Additionally, other individual characteristics will be examined for their influence on the effects of variety and portion size on meal intake.

Official Title
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Combined Effects of Variety and Portion Size on Meal Intake of Women

Conditions
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Eating Behavior

Intervention / Treatment
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* Other: Sequential Variety
* Other: Simultaneous Variety
* Other: Single Food
* Other: Small portion
* Other: Large Portion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Be willing and able to travel to Penn State University Park campus weekly for meals Be fully vaccinated against COVID-19 Be a woman 20 - 65 years old Regularly eat 3 meals/day Be willing to refrain from drinking alcohol the day before and during test days Have a body mass index between 18.0 and 35.0 kg/m*m Be willing to refrain from eating after 10 pm the evening before test sessions Be willing to participate in all study procedures Exclusion Criteria: Must not be a smoker Must not be an athlete in training Must not be pregnant or breastfeeding at the time of screening Must not have taken prescription or non-prescription drugs that may affect appetite or food intake within the last 3 months Must not dislike or be unable to eat the test foods (because of allergies, intolerance, or dietary restrictions) Must not have a high variability in liking of the test foods Must not be currently dieting to gain or lose weight Must not have a health condition that affects appetite Must not have participated in a similar study in our lab in the past year Must not be a student, faculty, or staff member in nutritional sciences or psychology

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 65 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 |
| --- | --- |
| Experimental: Sequential Variety, Small Portion<br>3 courses each consisting of a different food served in a small portion. | Other: Sequential Variety<br>* 3 courses each consisting of a different food<br>Other: Small portion<br>* Small meal portion size<br>|
| Experimental: Sequential Variety, Large Portion<br>3 courses each consisting of a different food served in a large portion. | Other: Sequential Variety<br>* 3 courses each consisting of a different food<br>Other: Large Portion<br>* Large meal portion size<br>|
| Experimental: Simultaneous Variety, Small Portion<br>3 courses each consisting of 3 foods served in small portions. | Other: Simultaneous Variety<br>* 3 courses each consisting of 3 foods<br>Other: Small portion<br>* Small meal portion size<br>|
| Experimental: Simultaneous Variety, Large Portion<br>3 courses each consisting of 3 foods served in large portions. | Other: Simultaneous Variety<br>* 3 courses each consisting of 3 foods<br>Other: Large Portion<br>* Large meal portion size<br>|
| Experimental: Single Food, Small Portion<br>3 courses each consisting of the same food served in a small portion. | Other: Single Food<br>* 3 courses each consisting of the same food<br>Other: Small portion<br>* Small meal portion size<br>|
| Experimental: Single Food, Large Portion<br>3 courses each consisting of the same food served in a large portion. | Other: Single Food<br>* 3 courses each consisting of the same food<br>Other: Large Portion<br>* Large meal portion size<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in intake by weight | Weight (grams) of all meal components consumed | Weeks 1, 2, 3, 4, 5, 6 | 
| Change in energy intake | Energy intake (kilocalories) of all meal components consumed, calculated from weight and energy density | Weeks 1, 2, 3, 4, 5, 6 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in bite count | The number of bites of food during the meal | Weeks 1, 2, 3, 4, 5, 6 | 
| Change in meal duration | Duration of the meal in minutes | Weeks 1, 2, 3, 4, 5, 6 | 
| Change in mean eating rate | Mean food intake per minute (grams/minute), calculated by dividing meal food intake by meal duration | Weeks 1, 2, 3, 4, 5, 6 | 
| Change in mean bite size | Mean food intake per bite (grams/bite), calculated by dividing meal food intake by bite count | Weeks 1, 2, 3, 4, 5, 6 | 
| Change in sip count | The number of sips of water during the meal | Weeks 1, 2, 3, 4, 5, 6 | 
| Change in mean drinking rate | Mean water intake per minute (grams/minute), calculated by dividing meal water intake by meal duration | Weeks 1, 2, 3, 4, 5, 6 | 
| Change in mean sip size | Mean water intake per sip (grams/sip), calculated by dividing meal water intake by sip count | Weeks 1, 2, 3, 4, 5, 6 | 
| Change in switching between bites and sips | The number of switches between bites and sips during the meal | Weeks 1, 2, 3, 4, 5, 6 | 
| Change in switching between different foods | The number of switches between different foods | Weeks 1, 2, 3, 4, 5, 6 | 
| Change in rating of pleasantness of the taste of food samples | Measured on a 100-mm visual analogue scale ranging from not at all pleasant (0 mm) to extremely pleasant (100 mm). This will be used to calculate Sensory-Specific Satiety | From before the test meal to after the test meal in weeks 1, 2, 3, 4, 5, 6 | 
| Change in rating of prospective consumption of food samples | Measured on a 100-mm visual analogue scale ranging from none at all (0 mm) to a very large amount (100 mm), in answer to How much of [this food] do you want to eat right now?. This will be used to calculate Sensory-Specific Satiety | Time Frame: From before the test meal to after the test meal in weeks 1, 2, 3, 4, 5, 6 | 
| Change in rating of hunger | Measured on a 100-mm visual analogue scale ranging from not at all hungry (0 mm) to extremely hungry (100 mm) | Time Frame: From before the test meal to after the test meal in weeks 1, 2, 3, 4, 5, 6 | 
| Change in rating of thirst | Measured on a 100-mm visual analogue scale ranging from not at all thirsty (0 mm) to extremely thirsty (100 mm) | Time Frame: From before the test meal to after the test meal in weeks 1, 2, 3, 4, 5, 6 | 
| Change in rating of nausea | Measured on a 100-mm visual analogue scale ranging from not at all nauseated (0 mm) to extremely nauseated (100 mm) | Time Frame: From before the test meal to after the test meal in weeks 1, 2, 3, 4, 5, 6 | 
| Change in rating of fullness | Measured on a 100-mm visual analogue scale ranging from not at all full (0 mm) to extremely full (100 mm) | Time Frame: From before the test meal to after the test meal in weeks 1, 2, 3, 4, 5, 6 |