The purpose of this randomized controlled trial is to assess the impact of different nutrient profiles for magnifying glass front-of-package labels (FOPLs) on consumer choices in an online grocery store. Participants will be adults residing in Brazil recruited through a survey research firm. Participants will be randomly assigned to one of three shopping environments in an online grocery store. Participants will complete a shopping task (selecting items from a pre-specified shopping list) in the online grocery store. After completing the shopping task, participants will be rerouted to a computer survey. The survey will include standard behavior and label perception questions, as well as demographic items.

Among noncommunicable disease, cardiovascular-related diseases are the leading cause of death worldwide and contribute to almost one-third of deaths in Brazil. Cardiovascular disease has become the leading cause of death in Brazil since 1960 due in part to poor eating habits, obesity, and insufficient physical activity. Consumption of high levels of sodium, added sugar, and saturated fat is a major driver of the development of cardiovascular disease. In this context, nutrition policies and interventions, such as the use of warning labels, are an important tool for reducing risk of diet-related diseases. The Brazilian Ministry of Health has recently announced efforts to combat the country's growing burden of diet-related noncommunicable diseases, and Brazil's National Health Surveillance Agency (ANVISA) has approved a more transparent and accessible system for communicating nutrition information for foods and beverages. The proposal will require labeling with a magnifying glass symbol on the front of products' packages to inform consumers about excess nutrients (i.e., sodium, sugar, saturated fat). Similar interventions have been implemented across Latin America, including Chile, Peru, and Mexico. A recent study in Chile demonstrated a reduction in purchases of food and drink items displaying warning labels.

This study seeks to test the effectiveness of different nutrient profiles to determine which products should carry the new labels in Brazil (i.e., the Pan-American Health Organization's profile or Brazil's National Health Surveillance Agency's proposed profile). Additionally, it seeks to assess whether the inclusion of information about products' ultra-processed nature further impacts consumers' product perceptions. The study will provide critical information for the Brazilian Ministry of Health on the effectiveness of the new label proposal and on strategies to inform Brazilians of product healthfulness.

Participants will be initially redirected from Cint (an online panel company). Following online consent and completion of a screening survey, participants will be redirected to an experimental online grocery store (Saruê), given a shopping list, and asked to shop for the items on the list as if in a real store. Upon redirection from Cint, participants will be randomly assigned into three arms: 1) control (no FOPLs); 2) FOPLs applied to products based on Brazil's National Health Surveillance Agency (ANVISA)'s nutrient profile model; or 3) front-of-package labels applied to products based on the Pan-American Health Organization (PAHO)'s nutrient profile model. After participants select products and check out, they will answer a survey about their perceptions about the labels and products carrying them. These questions will include self-reported responses to the content (e.g., elaboration, beliefs). After data collection, data on participants' selected products in the online grocery store will be analyzed to determine which nutrient profile was the most effective in decreasing participants' consumption of key nutrients.

Setting: The trial will take place in Saruê, an experimental online grocery store created for researchers to examine how front-of-package labels influence consumer purchases in a controlled but realistic environment. The online store reflects real-world prices and is modeled after Pão de Açúcar, a Brazilian online grocery store .

Recruitment: Participants will be recruited through Cint, a survey research firm. The eligibility criteria are residing in Brazil, being 18 years or older, and being responsible for at least half of the grocery shopping for one's household. Participants are ineligible if they were involved in any pre-testing related to the survey. Experiments conducted using online convenience samples, such as those recruited by Cint, largely replicate findings from studies conducted via probability-based samples. Cint will screen for eligibility and recruit participants from their pool of 8 million participants in Brazil. Approximately 3,000 participants will be recruited. As compensation, participants will receive incentives or points that can be redeemed for gift cards or goods per Cint's protocols.

Informed Consent: Participants will sign an informed consent form that follows a structure that is customary in Brazil.

Randomization: After the participant has signed the consent form, they will be randomly assigned to one of the three study arms. Randomization order will be determined a priori. Participants will have an equal chance of being randomized to each trial arm.

Inclusion Criteria:

• 18 years or older
• Resides in Brazil
• Does at least half of the grocery shopping for their household

Exclusion Criteria:

• Involved in any pre-testing