On top of reading what's here, I'd like to add my own two cents. You're probably young--i.e.you don't have any plans for a specialty, a family, etc. That's just the way they want you. The military is looking to make you commit the next 12 (!) years of your life before you even know anything about what you want to do with it. Do you want to leave your family at the military's whim? You may say to yourself you don't plan on having one till you're older, but how old exactly do you want to be? How do you plan to compromise with your spouses's career? Would you be happy not getting the specialty or fellowship you want to do simply because it's not in the military's best interests? All of these issues and alot more are very prevelant, and believe me that once you sign they don't care much about your preferences and interests. Don't listen to your recruiter's BS about how easy basic training will be (great way to spend your last free summer... not), how people get what specialties they want, or how you won't be stop-lossed (forced to stay on) or pulled from IRR. Yeah, IRR pullouts for doctors hasn't happened yet, but I think we all know it's coming.
Now, according to information posted in other forums, doctors have the lowest rates of defaulting on student loans. All of your classmates will take loans, and all of them will come out and be practicing doctors who will make a good amount of money. Don't get some kind of phobia against taking loans, but then again this is what recruiters want. Give up decisions regarding where and in what you want to train and practice (which will influence your entire career) just to forego loans totalling a year's salary for an average doctor. When you decide what you want to do in the civilian world, there will be no anxiety about what to do and where to do it. That's completely different from the anxiety that people have here.
If you really want to do it, wait for other options. There are other ways to serve your country than to serve your military. Even with that being said, you can wait awhile and then join. You don't need to join the first year of medical school. The ideal candidate in my eyes is someone who has some reason why they must be in the military. They told my loved one on the first day of OBC that being an officer comes first and being a doctor comes second. I think it would serve the pre-meds thinking about military med well if they though about it the same way.
My two cents out.