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OpenTrials
Completed

NCT Number: NCT06263621

Changing Portion Size Descriptions in a Cafeteria

The goal of this this intervention is to test the degree to which a portion size labeling intervention influences consumer selection of smaller portions at two large cafés. The main question it aims to answer is: Do consumers order fewer calories when the portion size label for the smaller entree is called "standard" instead of "small"?

Participants will order lunch as usual in the two cafes (one intervention, one control) for 5.5 months, and all order items will be recorded in the check-out system. One cafe will receive the labeling intervention, while the other will not. Researchers will compare the average calories per order between the two cafes to see if there are differences.

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Key information

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Courtyard Cafe, Boston, Massachusetts, United States

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About this study

The investigators will work with two cafés that will start offering two size options for their entrées. The cafés will go through three phases: a baseline phase where there are two portion sizes and no intervention (6 weeks), an intervention phase where the portion size labeling strategy will be implemented (7 weeks), and then a final phase where the portion size intervention is removed (7 weeks). During the baseline period, the smaller-sized entrée will not receive a label, and the larger-sized entrée will be called "Large." During the intervention period for the control café, labeling will stay the same, but in the intervention café, the smaller size will be labeled "Standard" and the larger size will be called "Large." In the post-intervention period, the smaller-sized entrée in the intervention café will have no label so that it resembles the control café.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • All customers who make a lunch purchase at the cafes

Exclusion criteria

  • Purchases made outside of lunch service.

Treatment and study plan

Intervention "Standard"

Behavioral

The two cafes will offer entrees in two sizes, a smaller and larger size. In the intervention cafe, the smaller size will be labeled "Standard" during the intervention period, and "Small" during all other times. In the control cafe, the smaller size will always be labeled "Small." The larger size will always be labeled "Large" for both cafes during the duration of the study.

Other names: "Standard"

Primary outcomes

  1. Average kcal per entree sold

    Time frame: Daily sales data for 5.5 months

    The primary outcome will be the average kcal per entrée purchased.

Secondary outcomes

  1. Number of entrée units purchased

    Time frame: Daily sales data for 5.5 months

    Analyzing the number of entrée units purchased will enable the investigators to assess the impact of the intervention on entree sales.

  2. Total kcal per transaction

    Time frame: Daily sales data for 5.5 months

    This will allow the investigators to examine whether participants who ordered a reduced-sized entrée were ordering more calories in other parts of the meal (i.e., a dessert).

  3. Weekly gross sales

    Time frame: Daily sales data for 5.5 months

    This will allow the investigators to assess whether the addition of a reduced-sized entrée at a lower cost negatively affected lunch service revenue.

Sponsors and collaborators

Lead sponsor

University of Pennsylvania

Other

Collaborators

  • Restaurant Associates

Registry information

Official study title

Changing Restaurant Portion Size Descriptions to Encourage Selection and Intake of Smaller Meals: a Field Experiment

Important dates

Study start
2024
Primary completion
2024
Study completion
2024
First posted
Feb 16, 2024
Registry last updated
Jul 11, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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