Elizabeth Hurley has to make "more effort" to look good now she is over 40.

The 46-year-old model-and-actress credits getting sufficient sleep as essential for maintaining her youthful looks and admits she has had to change all her habits as she has gotten older.

She said: "I love women looking fabulous and I don't think growing older means looking less good. For me, it's less about trying to looking younger and more about making sure you look your absolute best. 

"Without doubt, once I hit 40 I had to make more effort and it wasn't until then I realised how much easier it was when I was younger.

"Now, I look like a lunatic if I don't get at least double that. In my 20s I used to be able to exist on coffee, cigarettes and crisps, but again, a couple of days of that now and I'd look and feel really scary!"

Elizabeth - who has a nine-year-old son Damian from a previous relationship - also admitted she constantly thinks about food and claims to eat much more than her fiance, former cricketer Shane Warne.

She added in an interview with Zest magazine: "Shane is very disciplined when he has to be but, bizarrely, I eat at least three times more than him because I'm far greedier and think about food all day long.

"He's naturally very athletic because he's been a professional sportsman for over 20 years. He keeps threatening to make me run with him, but I've resisted so far!"

Despite her love of food, the 'Austin Powers' star admits she puts "pressure" on herself to stay slim because she continues to model her swimwear line.

She said: "I put myself under pressure to remain slim because I still model my own bikinis but it is much more difficult to feel motivated in the gloomy winter.

"I wrap myself up and try to walk every day with my dogs and sometimes force myself to run a bit - but I hate it. I love Pilates and yoga but, again, am more likely to do them in the spring and summer."