XmisterIS, that's true but somehow they still manage to look reasonably healthy. I think it has something to do with the relationship with the outdoors.
I'm as guilty as anyone. I left the UK a decade ago now. Before that I worked in an office and commuted by car, all fairly typical. The first thing I realised was that I'd spent my time at university and work barely noticing the seasons as they went by, except for the fact it may or may not have been dark when I arrived at the pub or left work. Here (Switzerland) still has a real relationship with the outdoors, not just activity-wise but even still eating seasonally despite the fact you can get imported foods. Life still maintains that rhythm and the year has a pattern, it's comforting and feels somehow "right" to be part of the world around you.
I did cycle in the UK but nowhere near as much as I do here. I was a bit overweight but considered myself reasonably fit. It was a real shock when I first went out with work colleagues for a mountain bike ride. These were guys in their 40s, 50s and early 60s and didn't do any particular exercise and worked in an office. Their basic fitness levels meant they had no problem at all punting a mountain bike along at 20-25kph for most of the day - I struggled, despite being in my late 20s at the time.
Imagine doing that in a typical office in the UK? Apart from the fact you'd have any number of health-related excuses for not doing it in the first place, i doubt it'd last half an hour.
Our whole way of living in the UK is killing us or at least ensuring that we don't get the most out of life. This is actually what is stopping me returning, despite the fact I miss my parents who are knocking-on a bit now. I could very easily see myself falling back into those ways. I also want a family and for them to grow up with this kind of lifestyle as normal and regard things like cycling as a normal part of life and not the occupation of oddballs, hippies and fitness freaks (or even specifically as "a leisure activity).
Britain saddens me a bit now actually, especially when I see the health of people I knew decline through their own actions. I know you can't live anyone else's life for them, but I'd really like them to have had the opportunities to see things from the point of view I've had.