Clinical trial NCT06263621: Changing Portion Size Descriptions in a Cafeteria
Official title: Changing Restaurant Portion Size Descriptions to Encourage Selection and Intake of Smaller Meals: a Field Experiment
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Food Selection
Obesity
Weight Gain
Food Preferences
Keywords: portion size, choice behavior, energy intake, food labeling
Lead sponsor: University of Pennsylvania
Sponsor class: OTHER
Collaborators: name: Restaurant Associates
First posted: 2024-02-16
Enrollment: 101481
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Entrees are offered in two different portion sizes at two cafes. The cafes were randomized to either receive the "Standard" portion label for the smaller size (Intervention) or the "Small" portion label for the smaller size (Control). The larger portion was labeled "Large." Daily lunch transaction data will be provided by the cafes.
Primary purpose: PREVENTION

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.

Eligibility criteria: Inclusion Criteria:

* All customers who make a lunch purchase at the cafes

Exclusion Criteria:

* Purchases made outside of lunch service.

Primary outcomes:
measure: Average kcal per entree sold
timeFrame: Daily sales data for 5.5 months
Secondary outcomes:
measure: Number of entrée units purchased
timeFrame: Daily sales data for 5.5 months
measure: Total kcal per transaction
timeFrame: Daily sales data for 5.5 months
measure: Weekly gross sales
timeFrame: Daily sales data for 5.5 months
Other outcomes:
Locations:
city: Boston
country: United States
facility: Courtyard Cafe
state: Massachusetts
city: Boston
country: United States
facility: Elements Cafe
state: Massachusetts
Study officials:
affiliation: University of Pennsylvania
name: Sophia V Hua, PhD, MPH
role: PRINCIPAL_INVESTIGATOR
References: