You hit the nail on the head. My son was diagnosed ADHD back in the early 80's. I have no doubt that he does have this disorder. We attended several seminars and support group meetings. One of the doctors that facilitated one of our meetings, a neurologist from the Cleveland Clinic, talked about the differences in the brains of ADHD people vs. non-ADHD. It is a REAL thing. I used to be very skeptical til I did a lot of research. However....
It absolutely is over diagnosed. Additionally, I do not subscribe to drug therapies for this problem so readily. As you pointed out so rightly, the lifestyles of modern American families are not conducive to people with lots of energy to burn off. Even normal kids need to run and play. This does not occur anymore like it did years ago.
Lastly, one of the biggest problems with ADHD and why I think it seems so much more prevalent today is directly related to the helter-skelter lives most kids live now. Routine, stability, consistency, and so on are important for most people. When I was a child, we ate dinner at the same time every night, give or take maybe 15 minutes max. Nowadays, it's a miracle if families even sit down to a dinner. And, also, as you said, the screwed up family lives of many of today's children do not lend themselves to a very consistent or stable life.
I don't happen to believe it's so much the diet, though obviously lots of sugar, like in sodas, and, worse, caffeine, is not a good thing for children, but I think the family stability and having a routine is the big culprit here.
Sorry for rather long post.
"talked about the differences in the brains of ADHD people vs. non-ADHD. It is a REAL thing. "
It absolutely is.
Problem is, the only way to absolutely verify that it really is ADHD is with a brain scan. There are clinics which are starting to do this.
"I do not subscribe to drug therapies for this problem so readily."
The brain is constantly re-wiring itself and changing itself based on environmental stimulus. It has the capability to overcome ADHD in all but the worse cases IM(NS)HO. But it takes a long time, alot of work, and it is just downright difficult to do. Most parents work two jobs and don't have time or training to try and help a child re-wire their brain over a significant period of time. It's easier to just give them some medication, and the meds look like a miracle drug.
The problem is that the kids never learn how to cope and they are sentenced to a lifetime of meds with serious side effects, not to mention the meds tend to rob them of their childhood.
For interesting reading on this subject, there's a book called "Social Intelligence". It's not about ADHD, it's about how the brain works.