Objective: The study analyzes e-health message content shared by university health centers and determines college students' engagement with those messages. Method: Using the Reasoned Action Approach (RAA) framework, the current study content analyzed the RAA components (target behavior, attitudes/expectancies, social norms, and efficacy) within Instagram messages that were shared by official university health services accounts to promote health behaviors among college students. Results: Results showed that university health services are often using RAA-informed message strategies, with just under half of all posts containing at least one RAA component. Also, students are more likely to engage with university health services content that includes positive expectancies--specifically, improved academic performance and general efficacy. Conclusion: The present research will help university health services tailor their theory-driven messaging to improve student engagement with their e-health content.