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Kate Beckinsale

Actress Kate Beckinsale always packs a brick of Kerrygold butter when she travels as she's convinced it helps her maintain her looks.

The ageless Underworld star, 45, never leaves home without the Irish brand's dairy product, explaining it's becoming more and more difficult to get.

She tells People, "If I'm going from one city to another I'll put some in my suitcase to make sure I have it. I'm the crazy person traveling with butter!"

Kate started making sure she had a slab of butter with her at all times after a low-fat diet on the set of Pearl Harbor in 2001 left her feeling and looking old.

"They (producers) had me on a very strict low-fat diet," the British beauty recalls. "I remember my mom coming and visiting me and going, 'You look so old'. I was 24 and I had lines on my face, because I didn't have enough fat.

"And so now, I remember very early on meeting a great nutritionist and they said, 'One day everyone is going to say don't eat low-fat margarine or they are going to say eat butter or eat olive oil'. And it did take quite a long time, but I really noticed if I can eat coconut oil and butter and things like that, obviously in moderation, it makes almost an immediate effect on your skin (sic)."

Kate admits she isn't much of a cook, but whenever she gets the urge to hit the kitchen she tends to whip up a fat-rich baked dessert.

"I make really good brownies and my mom makes this crazy English thing called a trifle for the holidays," she smiles. "It's very alcoholic and squishy. And so we always make that."