10/12/2016 12:57 AM AEDT

Gigi Hadid Reveals She Has Thyroid Disease

Gardiner Anderson/Bauer-Griffin via Getty Images
Gigi Hadid reveals she has thyroid disease

Gigi Hadid is opening up about her battle with Hashimoto's disease.

Alongside Ruby Rose, Aly Raisman, Zoe Kravitz, and Lena Dunham, the 21-year-old supermodel revealed during a panel with Reebok that she has been battling the thyroid disease for the past two years and struggles to maintain a normal metabolism.

"My metabolism actually changed like crazy this year," Hadid told the #PerfectNever crowd on Wednesday. "I have Hashimoto's disease. It's a thyroid disease, and it's now been two years since taking the medication for it, so for the [Victoria's Secret] show I didn't want to lose any more weight, I just want to have muscles in the right place, and if my butt can get a little perkier, then that's good."

After walking in her second Victoria's Secret Fashion Show just weeks ago, Hadid was called out by fans for her thin figure.

At this point in her career, Hadid is no stranger to being body-shamed.

Recently, Tommy Hilfiger admitted to Yahoo! Style that he put Gigi in a poncho during his fall 2015 New York Fashion Week show because she wasn't thin enough.

Gigi Hadid walks the Fall 2015 Tommy Hilfiger show.

"Our casting director said, 'She doesn't really fit because you know she's not quite as tall as the other girls, she's not quite as thin,'" the 65-year-old designer told Joe Zee.

But the blond bombshell knows how to handle body shamers.

Gigi Hadid walks the runway during the Giambattista Valli show as part of the Paris Fashion Week Womenswear Spring/Summer 2016 on October 5, 2015 in Paris, France.

Nearly a year ago during Paris Fashion Week, Gigi was fighting a similar battle when body-shamers on Instagram posted negative comments about her appearance and size, criticizing her for having a body that's curvier than the average high fashion model.

"I represent a body image that wasn't accepted in high-fashion before, and I'm very lucky to be supported by the designers, stylists, and editors that I am: ones that know this is fashion, it's art; it can never stay the same," she writes. "If you don't like it, don't follow me, don't watch me, cause I'm not going anywhere."

A photo posted by Gigi Hadid (@gigihadid) on

As noted by Refinery29, Hashimoto's, also known as chronic lymphocytic thyroiditis, occurs when "someone's immune system attacks the thyroid gland."

In Hollywood, actresses Zoe Saldana, Victoria Justice, Gina Rodriguez and Nia Vardalos also battle with the same autoimmune disease.

Gigi's younger sister, Bella Hadid, who also walked the VS Fashion Show this year, is dealing with her own health problems.

The 19-year-old, along with mom Yolanda Hadid and brother Anwar, has chronic Lyme Disease, a tick-borne illness.

Bella Hadid walks the 2016 Victoria's Secret Fashion Show in Paris.

"It affected my memory, so I suddenly wouldn’t remember how to drive to Santa Monica from Malibu, where I lived," Bella said in an 2015 interview with ES Magazine. "I couldn’t ride [horses]. I was just too sick. And I had to sell my horse because I couldn’t take care of it."

But leave it up to the Hadid sisters to battle through their health issues and strut their stuff with confidence.

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