Culturally Appropriate Nutrition Communication for Mexican American Women

Perceived effectiveness of the message is known to affect intention to engage in a given health behavior. Therefore, perceived effectiveness of the stimuli was assessed as a proxy measure for intention to reduce sugary beverage consumption using a 5-point, 13-item Likert scale with responses ranging from Strongly Agree=5 to Strongly Disagree=1. This scale comprised 3 subscales namely (1) Message Acceptance - 2 items, (2) Argument Strength - 4 items, (3) Personalized Perceived Effectiveness - 7 items. Greater scores on this scale represented greater levels of perceived effectiveness of the message.

responses ranging from Strongly Agree=5 to Strongly Disagree=1. Two sample items from the scale are, "During viewing, I felt I could really get inside the person's head", and "At key moments in the video, I felt I knew exactly what they were going through". Greater scores on this scale represent greater degree of identification with the character in the video.

Activation of social justice values was measured using a 5-point, 2-item Likert scale with responses ranging from Strongly Agree=5 to Strongly Disagree=1. The two items are, "The message made me think that when I choose to eat healthy, I'm helping to make the world a better place" and "The message made me think that when I eat healthy, I'm doing my part to protect people who are being manipulated by sugary beverage companies". Greater scores on this scale represent greater levels of activation of social justice values.

Sugary beverage related media literacy was measured using a 5-point, 8-item Likert scale with responses ranging from Strongly Agree=5 to Strongly Disagree=1. This scale measured how much the participants understood the ways in which sugary beverage industry used media to influence and manipulate their sugary beverage consumption behaviors. Some sample items are as follows: "Certain sugary drink brands are designed to appeal to people like me", "Sugary drink ads show a healthy lifestyle to make people forget about the health risks, such as weight gain and diabetes" and "Sugary drink ads link drinking these beverages to things people want, like love, good looks, and power". Greater scores on this scale represent greater levels of sugary beverage media literacy.

Public health literacy is defined here as an understanding of the social determinants of health. This was measured using a 5-point and 7-item Likert scale with responses ranging from Strongly Agree=5 to Strongly Disagree=1. The seven items measured opinions about how much different external factors affect health because these best reflected an understanding of the social determinants of health: (1) money, (2) education, (3) safe and affordable housing, (4) early childhood experiences, and (5) government policies and programs (6) lifestyle choices and (7) consequences of system failure on the under-resourced. Greater scores on this scale represented greater levels of public health literacy.

Empowerment to engage in civic action was measured using a two-item index that assessed the perceived effectiveness of engaging in civic actions. Each question was a 4-point Likert item with responses ranging from "Very Effective=4" to "Very Ineffective=1". The two items were as follows, "How effective would it be to boycott sugary beverages as a way to convince corporations to stop pushing sugar to my community?" and "How effective would it be to use social media to convince corporations to stop pushing sugar to vulnerable groups?". Greater scores on this index represented greater levels of efficacy to engage in civic action.

Knowledge increases self-efficacy and empowers people to make better health choices for themselves and knowledge of the negative consequences of a given health behavior increases the intention to reduce that behavior. Therefore, better knowledge of the negative consequences of sugary beverage consumption directly impacts both individual level sugary beverage consumption as well as social level psychological empowerment to advocate for reduction in sugary beverage consumption at the community level. A sugary beverage knowledge scale comprised 6 true or false items adapted from multiple studies. The statements were as follows: Excessive sugar consumption causes, (1) health problems (2) weight gain (3) dental caries (4) diabetes (5) cancer and (6) heart disease". Greater scores on this scale represented greater levels of sugary beverage knowledge.

Engagement with the message was assessed with 2 items from the Narrative Transportation Scale (Green et al.).

Perceived similarity of the participant with the main character (poet/speaker) in the video was assessed with a 2-item scale adapted from Cohen and colleagues (2018).

Elaboration of the message arguments was assessed using a 4-point scale created by Kahlor and colleagues (2003) and a 3-point sugar-specific elaboration scale created by Dixon and colleagues (2015).