Provision of Small vs. Large Portion Sizes and Later Food Intake

Study Overview
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Brief Summary
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In 3 laboratory experiments the effect that receiving a small vs. large portion size of food has on later intake of that food was examined

Detailed Description
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Historical increases in the size of commercially available food products have been linked to the emergence of a worldwide obesity crisis. Although the acute effect portion size has on food intake is well established, the effect that exposure to smaller portion sizes has on future portion size selection is yet to be examined.We tested whether reducing a food portion size may 'renormalize' perceptions of what constitutes a normal amount of food to eat and result in people selecting and consuming smaller portions of that food in future. Across three experiments participants were served a large or smaller portion of food. In experiments 1-2, twenty four hours later participants freely selected and consumed a portion of that food. In experiment 3, one week later participants reported on their preferred portion size of that food.

Official Title
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Provision of Small vs. Large Portion Sizes and Later Self-selected Food Intake: 3 Experimental Laboratory Studies in UK Participants

Conditions
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Eating Behavior

Intervention / Treatment
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* Behavioral: Small portion size provision
* Behavioral: Large portion size provision


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 years or older Exclusion Criteria: History of food allergy, eating disorder or currently dieting to lose weight

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

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: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Small portion size provision<br>Participants in this arm are served a small serving of a lunchtime food to eat (session 1). | Behavioral: Small portion size provision<br>* The intervention is the small meal size participants are provided with during a lunchtime session in the laboratory.<br>|
| Active Comparator: Large portion size provision<br>Participants in this arm are served a large serving of a lunchtime food to eat (session 1). | Behavioral: Large portion size provision<br>* The intervention is the large meal size participants are provided with during a lunchtime session in the laboratory.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Later food intake (24 hour) | Amount of the lunchtime food later chosen and consumed | Measured 24 hours after random allocation (experiments 1 and 2) | 
| Later food intake (7 days) | Amount of the lunchtime food later chosen and consumed | Measured 7 days after allocation (experiment 3) |