Evaluation and comparison of the effectiveness of front-of-package labeling systems for pre-packaged and ultra-processed foods and non-alcoholic beverages in Cartago and San José, Costa Rica

ISRCTN ISRCTN12060665
DOI https://doi.org/10.1186/ISRCTN12060665
Secondary identifying numbers PAHOERC.0380.02-CRI
Submission date
06/07/2023
Registration date
17/07/2023
Last edited
10/07/2023
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Other
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English summary of protocol

Background and study aims
The study has been designed to understand how people perceive labels of food products. The objective of the study is to evaluate and compare the efficacy of front-of-package nutritional labelling systems in changing the choice of consumers in Costa Rica.

Who can participate?
Adult supermarket shoppers aged 18 years or older, residing in Costa Rica, and have no visual impairment.

What does the study involve?
Participants will be shown a series of images of packaged food products and will be asked to answer a series of simple questions:
- Which product would you buy?
- Which is the product least harmful to health?
- Is the content of any of the following nutrients in this product higher than recommended for a healthy diet? Sugar; Sodium; Total fat/fat; Saturated fat; Trans fat; None of the nutrients.
The survey will take approximately 15 minutes.

What are the possible benefits and risks of participating?
Participants will receive no direct benefit, but their participation may help us understand how people use food product labels when making decisions, which may result in benefits to the entire population. Participation does not imply any risk to participants.

Where is the study run from?
World Health Organization Regional Office for the Americas (USA)

When is the study starting and how long is it expected to run for?
April 2021 to January 2022

Who is funding the study?
1. The Pan American Health Organization (USA)
2. Resolve to Save Lives (Global)

Who is the main contact?
Karol Madriz Morales, kmadriz@inciensa.sa.cr

Contact information

Dr Fabio Da Silva Gomes
Scientific

525 23rd St NW
Washington DC
20037
United States of America

ORCiD logoORCID ID 0000-0003-4997-4642
Phone +1 2029743695
Email gomesfabio@paho.org

Study information

Study designSingle blinded parallel randomized controlled trial
Primary study designInterventional
Secondary study designRandomised parallel trial
Study setting(s)Other
Study typeOther
Participant information sheet Not available in web format, please use contact details to request a participant information sheet.
Scientific titleEffects of front-of-package nutrition labelling systems on objective understanding and purchase intention of food and non-alcoholic drink products in Costa Rica: randomized controlled trial
Study objectivesThe front-of-package nutritional labeling systems tested have:
1. A different efficacy in improving consumers' ability to correctly identify products with excessive amounts of sugars, fats, and sodium
2. A different efficacy in improving consumers' ability to correctly identify the product option that is the least harmful to health
3. A different efficacy in improving cosumers' purchase intention reducing the choice for products with an excessive content of nutrients associated with noncommunicable diseases (i.e. sugars, fats, sodium)
Ethics approval(s)

1. Approved 08/12/2021, Comité Ético Científico - Instituto Costarricense de Investigación y Enseñanza en Nutrición y Salud (INCIENSA) (Apartado 4-2250, Tres Ríos, -, Costa Rica; +506 2279-9911; sec_cec@inciensa.sa.cr), ref: IC-2021-02

2. Approved 22/12/2021, Pan American Health Organization Ethical Review Committee (PAHOERC) (525 23rd St NW, Washington DC, 20037, United States of America; +1 2029743548; pahoerc@paho.org), ref: PAHOERC.0380.02

Health condition(s) or problem(s) studiedImprovement on consumers' ability to correctly identify products with excessive amounts of sugars, fats, and sodium, to correctly identify the product option that is the least harmful to health, and to choose to purchase the least harmful choices or none of them options if they are all harmful.
InterventionAllocation is random at an equal rate (1/5) to five study groups (four experimental and the control group). The randomisation of the experimental conditions and groups was completed by adopting a Williams design to ensure the order of categories of products and the order of products within categories was random and balanced for all groups. This randomisation produced four random and balanced sequences of categories of products and products within categories used for each of the five groups, resulting in 20 possible combinations of groups and sequences (5×4), equally balanced and order within each group. Participants in each group are exposed to either one of the experimental conditions or allocated to the control group.

Participants in the experimental groups are shown two-dimensional (2D) images of 12 different mock-up products presented at random and balanced orders between and within categories of products. The mock-up products do not correspond to real commercial products available in the Costa Rican market but have similar characteristics in terms of package and graphic design and nutritional composition. Four sets of mock-ups are used. Each set includes three (3) products from each of four (4) product categories of ultra-processed products commonly consumed (3×4=12 mock-up products). The product categories are breakfast cereal extrudates, chocolate milks, crackers, and yoghurts. The same 12 mock-up products are used in each group; the only difference across groups is the front-of-package (FOP) labelling scheme they feature. Mock-ups shown to participants feature solely one of the following FOPL schemes tested, according to the group they are allocated to: black octagonal warning labels (OWL group), Nutri-Score (NUS group), traffic-light labelling (TFL group), guideline daily amounts (GDA group), or no FOP label (control group).
Intervention typeBehavioural
Primary outcome measureMeasured using responses obtained from respondents by the interviewers by means of the application of a structured questionnaire after they were shown two-dimensional images of mock-up products:
1. Product selection
2. Correct identification of sugars, sodium and/or saturated fats found to be in excess

Secondary outcome measuresGender, age and education level measured by structured questionnaire after they were shown two-dimensional images of mock-up products
Overall study start date27/04/2021
Completion date22/01/2022

Eligibility

Participant type(s)Healthy volunteer
Age groupAdult
Lower age limit18 Years
Upper age limit200 Years
SexBoth
Target number of participants1,325
Total final enrolment1351
Key inclusion criteriaAdult supermarket shoppers residing in Costa Rica aged 18 years old or older.
Key exclusion criteria1. Visually impaired people
2. Persons unable to give informed consent
3. People who deny being part of this study
Date of first enrolment14/01/2022
Date of final enrolment22/01/2022

Locations

Countries of recruitment

  • Costa Rica

Study participating centre

Minsiterio de Salud - Instituto Costarricense de Investigación y Enseñanza en Nutrición y Salud (INCIENSA)
Laboratorio Tecnología Nutricional
Unidad de Salud y Nutrición
Apartado 4-2250
Tres Rios
-
Costa Rica

Sponsor information

World Health Organization Regional Office for the Americas
Other

525 23rd St NW
Washington DC
20037
United States of America

Phone +1 (202) 9743815
Email nedervelee@paho.org
Website http://www.paho.org/hq/
ROR logo "ROR" https://ror.org/008kev776

Funders

Funder type

Government

Pan American Health Organization
Private sector organisation / International organizations
Alternative name(s)
Organización Panamericana de la Salud, PAHO
Location
United States of America
Resolve to Save Lives

No information available

Results and Publications

Intention to publish date01/12/2023
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot expected to be made available
Publication and dissemination planPlanned publication in a high-impact peer-reviewed journal.
IPD sharing planIndividual participant data will not be made available due to confidentiality.

Editorial Notes

10/07/2023: Trial's existence confirmed by Comité Ético Científico - Instituto Costarricense de Investigación y Enseñanza en Nutrición y Salud (INCIENSA)