Effects of Portion Size of Multiple Items at a Meal on Food Intake of Adults

Study Overview
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Brief Summary
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This study tests the effect of serving larger portions of all foods in a meal on the outcome of food and energy intake. Using a crossover design, participants are served the meal once a week for four weeks and the portion sizes are varied at each meal. Some of the foods served at the meal are low in calorie density (calories per gram) and some are higher in calorie density. The aim is to determine whether intake in response to larger portions differs depending on characteristics of the subjects or of the foods.

Conditions
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Feeding Behaviors

Intervention / Treatment
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* Other: Food portion size


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Body mass index of 18 to 40 kg/square meter Regularly eat three meals per day Willing to eat foods served at test meals Exclusion Criteria: Food allergies or restrictions Dieting to gain or lose weight Taking medications known to affect appetite Smoker Athlete in training Currently pregnant or breast-feeding Questionnaire score indicative of depression Questionnaire score indicative of disordered eating attitudes

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 45 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: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 100% Portion Sizes<br>Food portion size Test meal consists of baseline (100%) portion size of all foods | Other: Food portion size<br> <br> |
| Experimental: 133% Portion Sizes<br>Food portion size Test meal consists of portion sizes of all foods that are 133% the size of baseline portions | Other: Food portion size<br> <br> |
| Experimental: 167% Portion Sizes<br>Food portion size Test meal consists of portion sizes of all foods that are 167% the size of baseline portions | Other: Food portion size<br> <br> |
| Experimental: 200% Portion Sizes<br>Food portion size Test meal consists of portion sizes of all foods that are 200% the size of baseline portions | Other: Food portion size<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in meal food intake | Differences in weight of food consumed (grams) at the meals | Weeks 1, 2, 3, and 4 | 
| Differences in meal energy intake | Differences in energy of food consumed (kilocalories) at the meals | Weeks 1, 2, 3, and 4 | 
| Differences in meal energy density | Differences in energy density of food consumed (kilocalories per gram) at the meal | Weeks 1, 2, 3, and 4 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in hunger and satiety | Differences in ratings of hunger and satiety either before or after the meal, as assessed by 100-mm visual analog scales (mm) | Weeks 1, 2, 3, and 4 | 
| Differences in ratings of food properties | Differences in ratings of food properties (such as taste or healthfulness) as assessed either by 100-mm visual analog scales (mm) or ranking (rank order) | Weeks 1, 2, 3, and 4 |