Changing Portion Size Descriptions in a Cafeteria

Not Applicable

Completed

• Conditions: Weight Gain; Food Selection; Food Preferences; Obesity
• Interventions: Behavioral: Intervention "Standard"

• Registration Number: NCT06263621
• Lead Sponsor: University of Pennsylvania

Brief 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.

Detailed 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.

Study Timeline

• Study Start: 2024-01-11
• Study First Submitted: 2024-02-08
• Study First Submitted QC: 2024-02-08
• Study First Posted: 2024-02-16
• Primary Completion: 2024-05-29
• Study Completion: 2024-05-29
• Status Verified: 2024-07
• Last Update Submitted: 2024-07-10
• Last Update Posted: 2024-07-11

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 101481

Inclusion Criteria

• All customers who make a lunch purchase at the cafes

Exclusion Criteria

• Purchases made outside of lunch service.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Intervention "Standard"	Intervention "Standard"	The smaller entree is labeled "Standard" and the larger entree is labeled "Large."

Primary Outcome Measures

Name	Time	Method
Average kcal per entree sold	Daily sales data for 5.5 months	The primary outcome will be the average kcal per entrée purchased.

Secondary Outcome Measures

Name	Time	Method
Number of entrée units purchased	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.
Total kcal per transaction	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).
Weekly gross sales	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.

Trial Locations

Locations (2)

Courtyard Cafe; 🇺🇸 Boston, Massachusetts, United States

Elements Cafe; 🇺🇸 Boston, Massachusetts, United States