The Role of Satiety in the Effect of Portion Size on Intake

Study Overview
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Brief Summary
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The study uses a crossover design in which the portion size of food is varied at each meal. Across four test meals, subjects will be served four different portions of food, and intake will be determined from pre- and post-meal food weights. The first visit will be a screening visit, at which subjects will complete the consent form, have their height and weight measured, and rate the taste of the study food. Test meals will be scheduled once a week for four weeks. At visits 2-5, subjects will eat lunch and rate characteristics of the meal. At visit 6, subjects will complete various questionnaires. The objective of this study is to determine whether any individual characteristics related to satiety influence the effect of portion size on intake.

Official Title
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The Role of Satiety in the Effect of Portion Size on Intake

Conditions
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Feeding Behavior

Intervention / Treatment
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* Other: 100% Portion Size
* Other: 125% Portion Size
* Other: 150% Portion Size
* Other: 175% Portion Size


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 a man or woman 18 - 60 years old Regularly eat 3 meals/day Be willing to avoid alcohol the day before and during test days Have a body mass index between 18.0 and 35.0 kg/m-squared Be willing to refrain from eating after 10 pm the evening before test sessions Exclusion Criteria: A smoker An athlete in training Pregnant or breastfeeding at the time of screening Have taken prescription or non-prescription drugs that may affect appetite or food intake within the last 3 months Dislike or be unable to eat the test foods (because of allergies, intolerance, or dietary restrictions) Currently dieting to gain or lose weight Have a health condition that affects appetite Have participated in a similar study in our lab in the past year

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

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: 100% Portion Size<br>Test meal consists of baseline (100%) portion size of meal. | Other: 100% Portion Size<br>* Meal portion size at baseline<br>|
| Experimental: 125% Portion Size<br>Test meal consists of food portion size that is 125% the size of baseline portion. | Other: 125% Portion Size<br>* Meal portion size 125% of baseline<br>|
| Experimental: 150% Portion Size<br>Test meal consists of food portion size that is 150% the size of baseline portion. | Other: 150% Portion Size<br>* Meal portion size 150% of baseline<br>|
| Experimental: 175% Portion Size<br>Test meal consists of food portion size that is 175% the size of baseline portion. | Other: 175% Portion Size<br>* Meal portion size 175% of baseline<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in energy intake | Calculated energy intake (kcal) based on weight and energy density of food consumed | Weeks 1, 2, 3, and 4 | 
| Differences in intake by weight | Weights (grams) of all foods consumed | Weeks 1, 2, 3, and 4 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sensory-specific satiety | Change in taste pleasantness of eaten foods compared to uneaten foods | Weeks 1, 2, 3, and 4 | 
| Eating rate | Assessed from meal duration and number of bites taken | Weeks 1, 2, 3, and 4 | 
| Ratings of hunger and satiety | 100-point visual analog scales | Weeks 1, 2, 3, and 4 | 
| Ratings of sensory characteristics of the food | 100-point visual analog scales | Weeks 1, 2, 3, and 4 | 
| Ratings of meal characteristics | 100-point visual analog scales | Weeks 1, 2, 3, and 4 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Obesity, eating behavior, food, nutrition