"Why is sexiness and nudity applauded in a woman's youth and reviled in her maturity?" the 55-year-old supermodel wrote on her Instagram
Paulina Porizkova
Paulina Porizkova
| Credit: Sergi Alexander/Getty

Paulina Porizkova is feeling very comfortable in her own skin.

The supermodel, 55, opened up about body confidence in an Instagram post on Monday, sharing a naked photo of herself alongside a caption that was "inspired by the brouhaha" surrounding braless pictures actress Elizabeth Hurley, also 55, had recently posted to social media.

"When I was in my twenties and thirties, the less I wore - the more popular I was," she began in the caption. "In my forties, I could walk around practically naked and illicit nothing more than a ticket for public indecency."

"At fifty, I am reviled for it. 'Put on your clothes, grandma. Hungry for attention, are you? A little desperate here? You're pathetic,' " Porikova continued, referencing some of the negative comments she's received.

The former America's Next Top Model judge went on to ask, "Why is sexiness and nudity applauded in a woman's youth and reviled in her maturity?"

"Because of men," she wrote. "Men are biologically programmed to spread their seed, inserting themselves into fertile containers which advertise their viability through youth."

"And what does this say for women like myself, who need to be validated by the male gaze?
Insecure," Porizkova added. "The only thing that is pathetic here is allowing others to set your priorities."

She concluded her post with two hashtags that read "sexy has not expiration date" and "between JLo and Betty White."

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In the past, Porizkova has been outspoken about double standards in aging, particularly when it comes to women in the public eye.

"It's a full-time job — there's a lot of maintenance required," she said in her 2018 cover story with NewBeauty. "It sucks. When your entire life has consisted of looking good, aging publicly, in a word, sucks. This is not for the faint-hearted."

"I don't want to have to go to war with my looks. And I don't want to start trying to look 20 years younger. My life has been all about beauty. I always had to be something very specific on the outside and maintain that because of my livelihood," Porizkova said. "I'm constantly battling with myself internally saying, 'Come on, beauty is not that important! Let go of being so vain and focus more on the things you can do!' "

Earlier this week, the model shared a makeup-free photo of herself after she had "rolled out of bed," writing in the caption, "Aging, (looks) when your whole life has been about the way you look is not super rewarding."

"I'm trying my hardest to withstand barbs of having past my prime, because God dammit, I feel in my prime now!" she wrote in part. "The combination of my learning, maturing, and earning my wrinkles, combined with the way I look, I believe is the best balance I have ever had."