Graham on a poster for "The Hangover"

The 43-year-old actress returned to the US gambling capital in the Nevada desert to film the third installment of 'The Hangover', but finds it too superficial for her taste.

She said: "I don't like Las Vegas. People seem phony, they're spending all their money and it's sad. And it's also so cold with permanent air conditioning everywhere.

"I'm more the type who wants to be outside and look at a tree. I don't want to look at a machine."

Although she didn't enjoy the location, Heather especially liked the luxury trailers she and her co-stars - Zach Galifianakis, Bradley Cooper and Ed Helms - stayed in during filming.

When asked what was different this time round, she replied: "Well, we had much nicer trailers, they're gorgeous, you can live in there, they're so nice! And Zach has gone on a total health kick, he's Mr Healthy, he's observing this really strict diet.

"He's this crazy comedian, but now he's super health-conscious, he doesn't eat sugar or gluten."
Heather does admit to following a similar food ritual, but admits to indulging when on holiday.

She added: "I sort of am [like that]. It's sad! I didn't use to be like that. I'll eat candy but, because I feel better if I don't, I don't usually do it. But I go to Italy or somewhere that has the best bread ever, I will eat it, but I don't eat a lot of white flour on a daily basis."