The overall objective of this research is to evaluate the impact of gamification on the diet quality of food choices made by American adults in an online grocery shopping experiment. Participants will shop for 12 food items from a grocery shopping list determined by the research team in a simulated online grocery store designed for this experiment. Each product has a nutritional quality score based on the Guiding Stars algorithm. The experiment tests the gamification of the nutritional quality score. Participants exposed to gamification see one to five crowns illustrating the nutritional quality of the food and a scoreboard indicating the total number of crowns from foods in the participant's shopping basket. Participants will be assigned to experimental conditions of gamification (game or no game) and a fictitious budget ($30 or $50). The investigators will test if the game and the budget affect the dietary quality of their final shopping baskets. The experiment is a 2x2 experimental design. The investigators hypothesize that the presence of gamification will change the dietary quality of participants' final shopping baskets. The investigators hypothesize that a higher budget will change the dietary quality of the final shopping basket. The investigators also hypothesize that the game and higher budget together will change the dietary quality of the final shopping basket.

Participants will be assigned to one of four experimental conditions:

1. Game=No and Budget = $30
2. Game=No and Budget = $50
3. Game=Yes and Budget = $30
4. Game=Yes and Budget = $50.

Variables:

1. Game: Indicates exposure to the game (dummy variable)
2. Budget: Indicates exposure low ($30) or high ($50) budget constraint (dummy variable).
3. Total number of crowns: sum of the number of crowns associated with the 12 items included in participants' final shopping baskets (a continuous variable that ranges from 12 to 60).
4. Number of crowns: number of crowns associated with each of the 12 items included in participants' final shopping baskets separately (a continuous variable that ranges from 1 to 5).

The investigators will exclude from the analysis:

1. Participants who had more than or less than 12 items in their final shopping cart.
2. Participants who had four or more items from the same food subcategory in the final shopping basket.
3. Participants who spent more than 120% of the budget assigned to them.
4. Aged < 18 years
5. Do not have access to a personal computer, laptop, tablet, or mobile phone.
6. Participants who were not in the US when participating in the study.

Inclusion criteria:

1. Participants who had 12 items in their final shopping cart.
2. Participants who had less than four items from the same food subcategory in their final shopping basket.
3. Participants who spent 120% or less of the budget assigned to them.
4. Aged 18 or older
5. Have access to a personal computer, laptop, tablet, or mobile phone.
6. Participants who were in the US when participating in the study.

Deidentified individual participant data collected in this experiment will be shared upon reasonable request.

Beginning 9 months and ending 36 months following article publication, or as required by a condition of awards and agreements supporting the research.

Data will be available upon reasonable request. Proposals may be submitted up to 36 months of article publication. After 36 months, the data will be available at Tufts University data warehouse but without investigator support other than deposited metadata.