Is the response "I am fine, thank you. And you?" outdated?

This is what I learned from the middle school English class 10 years ago as the correct way to respond to "How are you?". The textbook was co-published by Longman, I suppose it was British English. When I go abroad I find few people say this.

Is this saying old fashioned or outdated?

I am fine, thank you. And you? is still used, but I consider it to be overly formal. It could also be considered very polite, however, and I would probably use a phrase similar to this as a response when being introduced to someone older than me, like a friend's parent or grandparent, for instance.

In the US, the short version of this phrase is a common response, especially with people you already know or see often: Fine, thanks. You?

Strangely, this phrase is in great use but most of the users are new to English. This particular response will almost immediately flag you as learning the language and people will very likely tone down their vocabulary and talking speed in an attempt to make things easier for you. It has the same vibe as, "My name is Matthew. What is your name?" or asking a child, "How old are you? Are you five?"

If you want a more commonplace phrase I think both HaL and snumpy have good suggestions.

While it is a perfectly acceptable answer in both the US and Britain, it is rarely used nowadays. Responses vary wildly depending on where you are and to whom you are speaking (race and age and environment (rural/suburban/urban) all seem to have an effect on the exact rendition of this basic greeting).

I believe the most standard response would be:

Fine, thanks. And you?

Though my generation typically entertains the following salutation:

Sup? (or Whassup?)
Not much. You?
Not much.