People's comments will definitely affect me as well, though the degree varies depending on what they say. I'm trying to work on not letting what people say get to me as much, but it's hard sometimes. One thing I've found is if I try to replace, or counteract their negative with a positive, sometimes it doesn't hurt so much. Trying to move on and not dwell on it very much has also helped me, because I'm the type of person that will go over the comment again and again, and if I don't allow myself to do this, it works out better. New schools are hard, but having friends to build you up has helped me immensely as well. It's not realistic to expect to have a best friend the first day, but if you try to put yourself out there, and be really friendly to people, then that will probably leave a lasting impression more than any eating habits.
Good luck!