A woman posted this photo of herself in trackies, and was cruelly shamed by gym worker.

A community care worker has expressed her outrage via social media after a gym employee mocked her stomach.

Posing in front of the mirror in tracksuit pants, a singlet and socks, Kayleigh Boase took a full-length photograph and uploaded it to Snapchat.

“Comfys on and chill,” she wrote.

When her phone buzzed later, follower Jowan Trahair had sent the picture back to her, cropped in tightly around her stomach.

“That belly,” he wrote. “You still training?”

When Boase responded that she’d “neglected core and cardio” workouts lately, he replied, “You used to be so sexy. Shame Kayleigh.”

Determined not to let his comments go unchecked, Boase shared a screenshot of the thread to her Facebook page.

"Idiots like this is what causes people to have eating disorders [sic]," she wrote. "Only an insecure bloke would try to belittle a woman. So screw you. I'm happy that's all that matters!"

Lindy West isn't afraid to take up space in the world. She speaks to Mia Freedman on No Filter. Post continues...

Speaking to The Sun, she said Kayleigh that Trahair's comments struck close to home.

“(It) mainly annoyed me as my mum has battled with bulimia since she was a teenager due to an inconsiderate bloke telling her she was fat and she took it to heart,” she said.

She reiterated, though, that she's perfectly happy with her body and determined not have her self-image manipulated by someone so judgemental.

“Everyone is beautiful in their own way," she said. "No one deserves to have their weight or size commented on.”