I'm a single adult male looking for a primary care doctor, and I don't know how to choose between a doctor specializing in family medicine, and one specializing in internal medicine.
As a doctor I would get a family medicine doctor. He can help you in various ways: not only he can certainly manage optimally your pathologies (if you have any), but also can give you advices on prevention and could help you with bureaucracy (at least here in Italy family medicine doctors are way more familiar with those things then internal medicine ones).
Even if you need an internal medicine doctor to manage any specific disease you may already have I still strongly support getting a family medicine one (which of course could interact with other specialists to treat your condition).
Internal medicine is to be considered a sub-speciality in my opinion and not an enhanced version of a family medicine one: they just have different roles.
A family doctor is basically your GP, your primary doctor whom you usually see first whatever happens. You visit him in his outpatient office or he visits you at home. A family doctor can make regular chekups, gives you advice and medications for sore throat and other non life-threatening conditions, or makes a diagnosis of a disease for treatment of which he/she will want to send you to hospital. A family physician also deals with common pediatric and gynecologic issues.
From your second article (acponline.org)
Required internal medicine training centers on common general medical conditions, but also includes significant experience in each of the internal medicine subspecialties (such as endocrinology, rheumatology, and infectious diseases) and neurology.
So, a family doctor is like a "wider profile" of a general practitioner who--beside common conditions in adults--also deals with children and gynecological problems on the outpatient level. On the other hand an internist is like a "general specialist" who should be able to treat certain more serious conditions, like peptic ulcer, angina, carpal tunnel syndrome, and usually works in a hospital (but could also be on the outpatient level).
Regarding training, a Family Medicine (FM) doctor and an Internal Medicine (IM) doctor who practices primary care are very similar. Both receive 3 years of residency training, in both the hospital and outpatient.
FM docs are also trained to work with kids. All things equal, IM docs will thus have proportionally more experience with adults. More generally, as said by other answerers, IM docs will usually have more experience with particularly sick adults.
The truth is, both are equally qualified to provide primary care for a healthy young adult male. It's hard to say that the quality of your care will be better from one or the other.
That said, the demographics of FM docs and IM docs are different. I don't wish to stereotype, so this mostly helps predict what you'll find if you're picking one at random - I wouldn't apply it to individuals. To repeat: I have the utmost respect for both professions, and I intend this to be as neutral as possible.
- IM docs are more likely to be young
- IM docs are more likely to have graduated from a foreign medical school, and/or to be a foreign national.
- 15% of FM doctors have a DO instead of an MD (as opposed to 5% for IM). It's controversial if there is a difference in quality, but DOs receive more training in massage and other body manipulations.
I have no source for this, but I'm gonna cite it as semi-common knowledge. I thought about leaving it off but it's a big deal to some people:
- Most physicians are at least somewhat disdainful of "alternative" therapies (at least the ones with insufficient research). This is still true in FM, but it's my experience that the rare doctor who does have an interest there is more likely to end up in FM. If you're big into alternative medicine I would lean towards FM, if you're not then don't let it scare you away. (Please read this paragraph as neutrally as possible; I don't want to start a derailing debate)
Conclusion: your care likely won't suffer either way, but you'll be choosing from a slightly different pool of personalities and demographics. Naturally, all of these are generalizations, individuals all differ.