Well, actually, as I've gotten bigger I've found that I spend less time in gym, only because my size is directly related to my knowledge level, and my knowledge has taught me that you don't need to spend 2-3 hours lifting weights every day like I did when I started.
Anyway, for me personally, I now spend 5 days/week in the gym, at around 90 minutes each.
As for diet/nutrition, once you have the knowledge about what to eat and what not to eat, there isn't all that much time put into thinking about it, beyond trying to think of new ways to make healthy food taste good so you don't get sick of the same thing.
I'd say the only additional time that a bodybuilder has to put into diet over Joe Schmoe is that the bodybuilder will typically prepare healthy meals himself, while Mr. Schmoe will drive through McDonalds.
Either way, I don't think it takes much longer once you know what you're doing.
So, factoring in 7-8 hours of sleep, 9 hours of work, and 90 minutes of exercise, that leaves me with about 5-6 hours to do "everything else" each day, which I find to be plenty.
Does it take effort and commitment? Sure. Does it have to consume your every waking minute? Absolutely not.
The primary thing that I keep consistent is making sure I'm eating every 2-3 hours. I absolutely despise feeling "hungry", I feel like my stomach is digesting my internal organs or something.
Either way, things stay pretty structured on their own in regards to nutrition once you have a system down. I eat basically the same things at the same times each day, but my primary concern is consuming enough calories to not only maintain 265 lbs. of body weight, but hope to gain additional mass beyond that.
If I were to spend a weekend away, and eat a normal 3 meals in a day like the ordinary folk, I would lose about 4-5 pounds over that weekend. (It has happened several times)
Training is very consistent based on the fact that I always workout at the same time each day (after work), and in the same location. However, methods of training are a different story.
Also, I noticed you applied the word "counterproductive" to skipping workouts once in a while, cheat meals, etc. These things are only counterproductive if they begin to happen more than "once in a while". If you're feeling run-down, skipping a workout isn't going to kill you, and it will probably help. Likewise, a "cheat meal" now and then won't do much harm either, especially if you're trying to gain muscle size. I would be more concerned that you're not eating enough, before I'd be concerned about you "cheating" on your diet once in a while.
Like I said, this stuff doesn't have to consume your daily life. Just take the time to learn how to eat, lift and rest properly, and it will just become a part of your life that you enjoy, not a hassle to try to juggle around and worry about.
I agree with Bauer97 in that after awhile it just becomes habbit. For example, throughout the week I'll spend 15 min each night preparing my food for the following day. That way when I wake up and am on the move all day, or at my office, I have food ready to be eaten every 3 hours or so. Plus, I don't have to worry about getting it ready in the mornings b/c I took care of it the night before.
At first it was kind of a hassle, that time spent each night prepping food...but now that it's been awhile since I've been doing it (4 years or so)...I couldn't imagine going an entire day having to worry about trying to find healthy food every few hours...