Celia Walden, journalist and wife to Sussex critic Piers Morgan, made the comment in her latest column. She also claimed Prince Harry has turned from “boyish” to “Yoda-like” during his recent endeavours.
The Duke and Duchess of Sussex shocked the nation last year when they decided to step down as senior members of the Royal Family.
Meghan and Harry launched their own non-profit foundation called Archewell.
The couple have also signed deals with the streaming giants Netflix and Spotify.
Writing in The Telegraph, Ms Walden said: “I’ve developed a fixation with Prince Harry’s brow.
“Over the past five years, it has gone from boyish and unfurrowed to Yoda-like: scored with the wisdom lines of someone thrice his age and weighed down by an almost unbearable number of responsibilities.”
Ms Walden labelled Harry and Meghan as the “biggest philanthropic duo” since Bill and Melinda Gates.
She wrote: “As one half of the biggest philanthropic duo since Bill and Melinda Gates, [Prince Harry] must knock back his kale smoothie… and set about saving the world.”
The American couple founded the Bill and Melinda Gates Foundation twenty years ago.
READ MORE: Prince Harry and Meghan Markle had ‘dismal’ exit from UK at first
The Sussexes could be aiming to make a similar impact across the globe with their own non-profit Archewell.
According to Meghan and Harry’s website: “At Archewell, we unleash the power of compassion to drive systemic cultural change.
“We do this through our non-profit work within Archewell Foundation, in addition to creative activations through the business verticals of audio and production.”
Last month, the Sussexes released the first episode of their Archewell podcast on Spotify.
In March, Page Six reported that Meghan and Harry hired a former Melinda Gates employee.
Catherine St Laurent served as director of brand and special initiatives for the Melinda Gates-owned Pivotal Ventures and has previously worked for the Bill & Melinda Gates Foundation.
The Sussex’s hired Ms St Laurent as chief of staff and executive director of their new foundation.
In an email which Page Six posted, Ms St Laurent said: “After nearly 9 years alongside Melinda and the Gates Foundation and Pivotal Ventures teams, I am moving on to begin a new chapter.
“Beginning next week I will be acting as Chief of Staff and Executive Director of the new non-profit enterprise for Meghan M and Harry.
“They are embarking on a new chapter themselves and I am thrilled to be able to play a supporting role in realising their vision and enabling them to achieve impact on the issues that matter the most to them.”