Samm Newman posted an image of her in her bra and boy shorts to share her self-confidence and encourage others to have positive body image.
"Fat is not a bad word," she told NBC 4. "How confident can you be if you keep censoring yourself because people don't want to look at you?"
"My Instagram, it was my safe place because when I was there, I could share anything," Newman said.
After users flagged the photos as inappropriate, Instagram disabled the account for "violating community guidelines" because of her clothing in the photo.
Its guidelines specifically stipulate that "accounts found sharing nudity or mature content will be disabled and your access to Instagram may be discontinued."
Newman said that it does not apply to her case, and the size 24 woman believes the double standard is size discrimination.
"I didn't find them or the bra at all inappropriate," Newman said. "They covered me entirely and I've seen pictures like that all over Instagram."
Instagram released a statement Monday apologizing for the "mistake."
"When our team processes reports from other members of the Instagram community, we occasionally make a mistake. In this case, we wrongly removed content and worked to rectify the error as soon as we were notified. We apologize for any inconvenience."
Newman's account has since been reinstated and is now private.