Influencers in Policy Fields on Social Media: Global Longitudinal Study of Dietary Sodium Reduction Posts, 2006-2022

Background: Excessive sodium intake is a major concern for global public health. Despite multiple dietary guidelines, population sodium intakes are above recommended levels. Lack of health literacy could be one contributing issue and contemporary health literacy is largely shaped by social media.

Objective: This study aims to quantify the posting behaviors and influence patterns on dietary sodium-related content by influencers in the policy field on X (formerly Twitter) across time.

Methods: We first identified X users with a scope of work related to dietary sodium and retrieved their posts (formerly Tweets) from 2006 to 2022. Users were categorized into the policy groups of outer-setting organization, inner-setting organization, or individual, based on their role in the conceptual policy field. Network analysis was used to analyze interactions among users and identify the top influencers in each policy group. A 4D influence framework was applied to measure the overall influence, activity, priority, originality, and popularity scores. These measures were used to reveal the user-level, group-level, and temporal patterns of sodium-related influence.

Results: We identified 78 users with content related to dietary sodium, with 1,099,605 posts in total and 14,732 dietary sodium posts. There was an increasing volume of sodium posts from 2010 to 2015; however, the trend has been decreasing since 2016, especially among outer-setting organizations. The top influencers from the three policy groups were the World Health Organization (WHO), the American Heart Association, and Tom Frieden. Simon Capewell and the WHO ranked the highest in activity; the World Action on Salt, Sugar, and Health and Action on Salt had the highest priority for dietary sodium content; General Mills and Tom Frieden had the highest originality; and WHO, Harvard University School of Medicine, and Tom Frieden received the highest popularity. Outer-setting organizations tend to interact with more users in the network compared to inner-setting organizations and individuals, while inner-setting organizations tend to receive more engagements from other users in the network than the other two groups. Monthly patterns showed a significant peak in the number of sodium posts in March compared with other months.

Conclusions: Despite the increased use of social media, recent trends of sodium intake education on social media are decreasing and the priority of sodium among other topics is low. To improve policy implementation effectiveness and meet recommended dietary targets, there is an increasing need for health leaders to consistently and collectively advocate for sodium intake reduction on social media.