Background- Communication messages today are all about influencing and persuading people. Two main types of messages can be seen when studying the healthy food trend on Instagram and how it is impacting attitude formation and change; these two are positive and negative messages. However, different communication messages are not the only deciders of attitude formation and change. There is one more significant factor that impacts attitude formation and change; this factor is identification with the message sender. Purpose- The purpose of this thesis is to identify whether positively or negatively themed messages on Instagram have a stronger impact on a person's attitudes regarding healthy food consumption. We will further examine if identification with the message sender additionally impacts attitude formation and change. Method- In order to fulfill the purpose of the thesis we used a qualitative research approach. We conducted interviews with 40 respondents that belonged to our main target group. Furthermore we conducted a robustness check with six respondents. All 46 respondents included in the qualitative study were Instagram users, and all the respondents in the main target group were students. Findings and Conclusion- After analyzing the empirical results together with suitable theories, some main conclusions could be drawn. The study demonstrated that positive communication messages are the preferred message type on Instagram. We further conclude that identification with the message sender does indeed have an additional impact on attitude formation and change. Based on this study we can say that communication messages and identification with the message sender work together in forming and changing attitudes regarding healthy food on Instagram. Practical Implications- This thesis gives valuable indications to companies, organizations and decision makers in order to direct marketing practices in terms of communication messages on social media, particularly Instagram. Moreover it gives insights for managers to be able to create communication messages that correspond to the expectations of the society. Keywords- Communication messages, attitude formation and change, identification with the message sender.