I don't see how what I saw was out of line with "reality," unless one is saying I'm lying. I was in Paris and London, and I barely saw any overweight people. There were a few, sure, but I don't think I ever saw a 400 or 500 pounder, which is a daily sight in the US. Now, I never travelled out of the major cities other than for a few tourist destinations--Shakespeare's home, Oxford, Versailles, etc.--so maybe it's different elsewhere, but I can't comment on what I didn't see.
Edit: After looking up statistics, it does look like the UK has its fair share of fat people. They have the second largest percentage in the world of obese people (still have a long way to overtake us, though). London must not be an accurate representation of the country as a whole. France, on the other hand, isn't that high on the list, so I don't think what I saw was too far off there. Maybe it's all the smoking.
Edit 2: Check this out. I found
this article about how much all humanity would weigh if they got on the scale. I found this quote particularly interesting:
North America has only 6 percent of the world's population, but 34 percent all the human biomass in the world that is due to obesity, the researchers said. In contrast, Asia has 61 percent of the world's population, but only 13 percent of the world's biomass due to*obesity
So, our fat people are way fatter than anyone else's. England may have a large percentage of obese people, but your 250 pounder is still put in the same category as our 400 pounder, which isn't rare.