Well tend to walk about 5-6 miles a day and do nothing else whatsoever and I'm in very good health.
I don't eat meat though so my metabolism is probably different.
Why do you maintain this is just a fad? I walk that same distance every day on my treadmill desk. It's helped my chronic back problem and it's better for my joints because it prevents bad posture. What's wrong with it?
You'll find out in about 10 years.
So you think it's a fad, fine. But why the hatred for it? Why do you think they're bad? Have you seen research that shows them to be unhealthy? Did you have a bad experience with them? I'm trying to understand what you feel is disadvantageous about them in light of my and others' experiences to the contrary.