I haven't noticed that at all.
I think it is more of a lifestyle thing - being a student again, for example.
I moved to the UK when I was in my late 30s, so I've become more careful about what I eat just because my metabolism isn't what it was when I was in my 20s.
I would probably have the same eating habits in the US as I do here in the UK.
An exception might be when you first move to the UK, you are trying all the new foods so you might eat more because everything is new and exciting.
But once UK food becomes "normal food" I think you're eating habits would reflect your particular lifestyle, not the fact that you live in the UK.
I also suppose that if you are homesick or experiencing culture shock, or just having a bit of difficulty getting used to certain things here and there, you might deal with your stress/depression/uneasiness by eating if you are the type of person that deals with those things by eating. But I, personally, deal with stuff in other ways.