Gwyneth Paltrow feels 'impending grief' about her children heading to college

Gwyneth Paltrow feels a "deep sense of impending grief" about her children heading to college.

The 51-year-old Goop founder has daughter Apple, 20, and son Moses, 18, with her 47-year-old with ex-husband Chris Martin, and is stepmother to producer spouse Brad Falchuk's children Brody and Isabella.

The lifestyle guru admits she has no idea what life will look like once her children fly the nest because motherhood has been her whole identity and "guiding force" for the past two decades.

Moses and Brody are heading to university later this year.

She told The Australian Women's Weekly magazine: "It'll be interesting to see how the morning routine changes with no kids in the house."

Asked how she feels about them flying the nest, she confessed: "On the one hand incredible sadness.

A deep sense of impending grief.

"On the other hand this is exactly what should be happening. Your kids are supposed to be, you know, young adults who can achieve and cope and make connections and be resilient.

That's exactly what you want. And that means they leave the house." So it's complicated? "Yeah. I've been so defined and so fulfilled by motherhood. It's been kind of the central... it's been like the central kind of... I don't know even how to articulate it! It's like the guiding force. It's what I return to."