This will vary among schools and departments/programs. I highly suggest contacting the school(s) and getting a sense of their policies (implicit or explicit). Some will be more clear about their policies. Columbia's Global Health Track, for example, does not allow other students in other tracks to be admitted into the GH Track once they have matriculated to the school. Also, I imagine that switching between one department (e.g., epidemiology) and another (e.g., health policy) may be different than switching between one program (e.g., health promotion) and another program (e.g., health behavior), if both are in the same department. Is the nutrition program in the same department as the sexual health program? In addition, professors who make decisions about who they will admit into their program may not be the same professors to which you wish to change. Are the sexual health folks in your program the same people who make the admission decisions to the nutrition program? You can see how difficult it would be. Also, my sense is that schools do not always allow switching programs because there may be a sense that one program is "easier" to get into. Once they are admitted into that program, they then switch to the "harder" program once matriculated. You can see how this can be frowned upon. Since it is still the application period, another course of action would be to hold your place in the sexual health program. Then, ask the admissions office if you can be considered for the nutrition program. This way if for whatever reason this is not possible or if you are denied admittance to the nutrition program you still have the sexual health program. At the end of the day, it does not hurt to ask. Contact them.In my personal statements for all of my health education/behavior/promotion applications, I pointed out that I was interested in sexual health (esp. developing programs to prevent the transmission of STIs).---This is something I have been set on since early undergrad. However, recently, my desires have been drifting towards designing nutrition education programs, working with Farm to School programs, etc. Now that I've been admitted and assigned an advisor, whose interests are in sexual health, what happens? Can I just contact the school/my advisor and switch my research interests within my health behavior program?
Also, I realized that some schools I've applied to have specific MPH programs in nutrition. How easy is it to change departments after being admitted?
WHY AM I HAVING THESE THOUGHTS?!?!