Evaluating Food Messaging Campaigns for Young Adults

实验性的：Counter-marketing messages

Participants will view a 10-week Instagram-delivered counter-marketing campaign exposing deceptive and harmful marketing practices used by food companies to sell sugary drinks and processed snack foods. Messages are drawn from those identified as most promising in prior message-development research and are targeted to values important to young adults (e.g., autonomy, respect).

行为的：Counter-marketing

Participants will receive messages focused on exposing and undermining deceptive, harmful, or misleading marketing practices used by food companies to sell unhealthy foods. Messages are delivered via Instagram posts.

实验性的：Health education messages

Participants will view a 10-week Instagram-delivered health education campaign about the health consequences of sugary drinks and processed snack foods. Messages are adapted from existing public health campaigns about these foods.

行为的：Health education

Participants will receive messages about the health consequences of sugary drinks and processed snack foods. Messages are delivered via Instagram posts.

有源比较器：Control (neutral) messages

Participants will view a 10-week Instagram-delivered campaign about fire and home safety, a topic unrelated to diet. Messages are adapted from existing public health campaigns about these issues.

行为的：Control (neutral) messages

Participants will receive messages describing neutral topic unrelated to food (fire and home safety). Messages are delivered via Instagram posts.

Diet quality (Healthy Eating Index-2020 score)

Overall diet quality calculated from up to two unannounced, nonconsecutive 24-hour dietary recalls (1 weekend day, 1 weekday) collected via NCI's Automated Self-Administered 24-Hour Dietary Assessment Tool (ASA24) at each time point. Healthy Eating Index-2020 scores reflect alignment with the US Dietary Guidelines for Americans; higher scores indicate healthier diet quality (i.e., greater intake of fruits, vegetables, whole grains, dairy, protein, and unsaturated fats and lower intake of saturated fat, sodium, added sugars, and refined grains).

Consumption of target food groups

Consumption of the food groups targeted in the campaigns (sugary drinks, processed sweet and salty snack foods) will be assessed using two unannounced, nonconsecutive 24-hour dietary recalls (1 weekend day, 1 weekday) collected via NCI's Automated Self-Administered 24-Hour Dietary Assessment Tool (ASA24) at each time point. Servings of each target food group will be calculated and summed such that higher values indicate higher consumption of the target food groups.

Internalized weight stigma

Survey items will assess internalized weight stigma using the 11-item Modified Weight Bias Internalization Scale (e.g., "I am less attractive than most other people because of my weight."). Responses will be measured on 5-point Likert scale ranging from "Strongly disagree" (1) to "Strongly agree" (5). Responses will be coded such that higher scores indicate higher internalized weight stigma. Responses to the 11 items will be averaged.

Disordered eating attitudes and behaviors

Survey items will assess disordered eating attitudes and behaviors using the Eating Disorder Examination Questionnaire (EDE-Q), a 28-item self-report questionnaire assessing the range, frequency, and severity of disordered eating attitudes and behaviors, including restraint, eating concern, shape concern, and weight concern. Responses will be measured on a 6-point scale, ranging from "No days" or "None of the times" or "Not at all" or "Not at all markedly" (each coded as 0) to "Every day" or "Every time" or "Markedly" or "Moderately" (each coded as 5). Following scoring guidance, global scores will be calculated as follows: analyses will sum responses within each of the 4 subscales (restraint, eating concern, shape concern, and weight concern), divide those scores by the number of items in the subscale, sum the subscale scores, and divide this sum by 4. Higher global scores indicate higher frequency or severity of disordered eating attitudes and behaviors.

Attitudes toward unhealthy food companies

Survey items will assess the extent to which participants feel positively or negatively toward food companies that sell unhealthy foods with 2 items: "How do you feel about companies that sell sugary drinks?" and "How do you feel about companies that sell processed sweet and salty snack foods?" Each item will be measured on a 5-point Likert scale ranging from "Very unfavorably" (1) to "Very favorably" (5). Responses to these items will be averaged. Higher scores indicate more positive attitudes toward unhealthy food companies.

Perceived alignment of healthy eating with values

Survey items will assess the extent to which participants view healthy eating behaviors (such as reducing their sugary drink consumption) as aligned with personal values such as autonomy and respect with two items: "When I limit how much I drink sugary drinks, I'm doing my part to disempower companies that try to cover up scientific evidence" and "When I limit how much I eat sweet and salty snacks, I'm doing my part to disempower companies that try to cover up scientific evidence." Responses will be measured on a 5-point Likert scale ranging from "Strongly disagree"(1) to "Strongly agree" (5). Responses to these items will be averaged. Higher scores indicate higher perceived alignment of healthy eating with values.

Externalized weight stigma

Survey items will assess the extent to which participants hold negative views about people with higher body weight using the 20-item Universal Measure of Bias - Fat Scale (UMB-FAT). Response items will be measured on a 5-point Likert scale ranging from "Strongly agree" (1) to "Strongly disagree" (5). Responses to these items will be averaged. Higher scores indicate higher externalized weight stigma.

Attribution of individual responsibility for weight

Survey items will assess the extent to which participants attribute responsibility for body weight to individuals using the 16-item Causal Attribution for Obesity scale. Response items will be measured on a 5-point Likert scale ranging from "Strongly agree" (1) to "Strongly disagree" (5). Responses to these items will be averaged. Higher scores indicate stronger attribution of responsibility to individuals for their body weight.