Changing Restaurant Portion Size Descriptions to Encourage Selection and Intake of Smaller Meals: a Field Experiment
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- University of Pennsylvania
- Enrollment
- 101,481
- Locations
- 2
- Primary Endpoint
- Average kcal per entree sold
Study Overview
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 Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Prevention
- Masking
- None
Eligibility Criteria
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •All customers who make a lunch purchase at the cafes
Exclusion Criteria
- •Purchases made outside of lunch service.
Arms & Interventions
Control "Small"
The smaller entree is labeled "Small" and the larger entree is labeled "Large."
Intervention "Standard"
The smaller entree is labeled "Standard" and the larger entree is labeled "Large."
Intervention: Intervention "Standard" (Behavioral)
Outcomes
Primary Outcomes
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
- Number of entrée units purchased(Daily sales data for 5.5 months)
- Total kcal per transaction(Daily sales data for 5.5 months)
- Weekly gross sales(Daily sales data for 5.5 months)
Investigators
Sophia Hua
Assistant Professor
University of Pennsylvania