United Kingdom, July 31 -- Martha Stewart has thrown shade at Meghan, Duchess of Sussex.

The 83-year-old has carved out a world-leading brand as a lifestyle guru and she has now hit out at Meghan after she launched her As Ever business, selling the likes of upmarket jam and wine.

Martha told Yahoo Lifestyle: "Meghan, I don't really know very well, and I hope she knows what she's talking about.

"Authenticity, to me, is everything, and to be authentic and knowledgeable about your subject matter is extremely important."

Martha also commented on 52-year-old Gwyneth Paltrow's Goop empire.

She said: "Gwyneth has been very successful; she created quite an interesting body of businesses.

"She's admired. She won an Oscar, for heaven's sake, ...