Effects of Variety and Portion Size on Meal Intake of Adults

Penn State University

Overview

The primary purpose of this study is to gain a better understanding of the combined effects of meal variety and portion size on food intake at a meal. The study will also explore 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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

SINGLE

Conditions

Eating Behavior

Interventions

Low varietyOTHER

Meal components are mixed together on the plate

High VarietyOTHER

Meal components are served separately on the plate

Small Portion SizeOTHER

Small meal portion size

Eligibility

Sex: FEMALEMin age: 20 YearsMax age: 65 Years

Medical Language ↔ Plain English

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 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

Locations (1)

Laboratory for the Study of Human Ingestive Behavior, The Pennsylvania State University

University Park, Pennsylvania, United States

Outcomes

Primary Outcomes

Change in intake by weight

Weight (grams) of all meal components consumed

Time frame: 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

Time frame: Weeks 1, 2, 3, 4, 5, 6

Secondary Outcomes

Change in bite count

The number of bites of food during the meal

Time frame: Weeks 1, 2, 3, 4, 5, 6

Change in meal duration

Duration of the meal in minutes

Time frame: 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

Time frame: 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

Time frame: Weeks 1, 2, 3, 4, 5, 6

Change in sip count

The number of sips of water during the meal

Time frame: 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

Time frame: Weeks 1, 2, 3, 4, 5, 6

Data from ClinicalTrials.gov

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Large meal portion size

With BeverageOTHER

Meal served with water

Without BeverageOTHER

Meal served without water

Change in mean sip size

Mean water intake per sip (grams/sip), calculated by dividing meal water intake by sip count

Time frame: 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

Time frame: 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

Time frame: 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 vary large amount (100 mm) 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

Change in rating of prospective consumption of the meal

Measured on a 100-mm visual analogue scale ranging from nothing at all (0 mm) to a large amount (100 mm) in answer to the question 'How much food could you eat right now?'.

Time frame: At the start of the test meal in weeks 1, 2, 3, 4, 5, 6

Change in rating of the size of the meal compared to participant's usual portion

100-point visual analog scale ranging from a lot smaller (0 mm) to a lot larger (100 mm)

Time frame: At the start of the test meal in weeks 1, 2, 3, 4, 5, 6

Change in rating of how filling the participant expects this amount of food to be

100-point visual analog scale ranging from not at all filling (0 mm) to extremely filling (100 mm)

Time frame: At the start of the test meal in weeks 1, 2, 3, 4, 5, 6

Change in rating of meal termination due to fullness

100-point visual analog scale ranging from strongly disagree (0 mm) to strongly agree (100 mm)

Time frame: At the end of the test meal in weeks 1, 2, 3, 4, 5, 6

Change in rating of meal termination due to eating their usual amount

100-point visual analog scale ranging from strongly disagree (0 mm) to strongly agree (100 mm)

Time frame: At the end of the test meal in weeks 1, 2, 3, 4, 5, 6

Change in rating of meal termination due to eating is no longer a priority

100-point visual analog scale ranging from strongly disagree (0 mm) to strongly agree (100 mm)

Time frame: At the end of the test meal in weeks 1, 2, 3, 4, 5, 6

Change in rating of meal termination due to there being no food left

100-point visual analog scale ranging from strongly disagree (0 mm) to strongly agree (100 mm)

Time frame: At the end of the test meal in weeks 1, 2, 3, 4, 5, 6

Change in rating of meal termination due to self-consciousness about amount consumed

100-point visual analog scale ranging from strongly disagree (0 mm) to strongly agree (100 mm)

Time frame: At the end of the test meal in weeks 1, 2, 3, 4, 5, 6

Change in rating of meal termination due to the food no longer tasting good

100-point visual analog scale ranging from strongly disagree (0 mm) to strongly agree (100 mm)

Time frame: At the end of the test meal in weeks 1, 2, 3, 4, 5, 6

Change in estimation of proportion of meal eaten

100-point visual analog scale ranging from 0% to 100%

Time frame: At the end of the test meal in weeks 1, 2, 3, 4, 5, 6

Change in estimation of calories consumed at the meal

Open ended question (number of calories)

Time frame: At the end of the test meal in weeks 1, 2, 3, 4, 5, 6