Changing Portion Size Descriptions in a Cafeteria

Obesity Clinical Trial

Official title:

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

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT06263621
• Other study ID #: 855090
• Status: Active, not recruiting
• Phase: N/A
• Start date: January 11, 2024
• Est. completion date: May 29, 2024

Study information

• Verified date: February 2024
• Source: University of Pennsylvania
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

Description:

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.

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 12000
• Est. completion date: May 29, 2024
• Est. primary completion date: May 29, 2024
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: N/A and older

Eligibility

Inclusion Criteria:

• All customers who make a lunch purchase at the cafes

Exclusion Criteria:

• Purchases made outside of lunch service.

Related Conditions & MeSH terms

• Food Preferences
• Food Selection
• Obesity
• Weight Gain

Intervention

Behavioral:
• Intervention "Standard"
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.

Locations

Country	Name	City	State
United States	Courtyard Cafe	Boston	Massachusetts
United States	Elements Cafe	Boston	Massachusetts

Sponsors (2)

Lead Sponsor	Collaborator
University of Pennsylvania	Restaurant Associates

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Average kcal per entree sold	The primary outcome will be the average kcal per entrée purchased.	Daily sales data for 5.5 months
Secondary	Number of entrée units purchased	Analyzing the number of entrée units purchased will enable the investigators to assess the impact of the intervention on entree sales.	Daily sales data for 5.5 months
Secondary	Total kcal per transaction	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).	Daily sales data for 5.5 months
Secondary	Weekly gross sales	This will allow the investigators to assess whether the addition of a reduced-sized entrée at a lower cost negatively affected lunch service revenue.	Daily sales data for 5.5 months