The model, actress and radio host, who starred as Lisa Hunter in the soap franchise between 2001 and 2006, said people messaged her on social media after her old scenes broadcast on Channel 4.
Atkinson, 35, said one man had told her she had been “fat” during her time on the series.
Speaking to Women’s Health UK magazine, she said: “For Hollyoaks turning 25 years old, they’ve been re-running some episodes, and they’ve had a week of my episodes, and people have actually DM’d me.
“A guy DM’d me, and he said: ‘Wow, I never realised at the time, but you were fat in Hollyoaks weren’t you?’
“I went back to him and I said: ‘Well, I was 15, so I was chubbier than what I am now, but please, please don’t let your daughter think that that’s your idea of fat. She will have problems for the rest of her life if that’s the case.'”
Atkinson, who is mother to one-year-old daughter Mia with Strictly Come Dancing’s Gorka Marquez, said she worried about her daughter growing up in the modern world.
The star told the magazine: “One of my biggest fears for Mia growing up, especially in the environment we’re all in now, with the Instagrams and the filters and the quick fix, these jabs and pills and stuff.
“It terrifies me that she’ll come to me and say: ‘Mum, I’ve read that if I do this injection it will make me thin.'”
Atkinson also recalled becoming a “nervous wreck” during the first months of her pregnancy.
“Growing and birthing a baby is the biggest workout you will ever do in your life,” she said.
“From the minute you find out you’re pregnant, I believe it’s a workout because you’re constantly trying to monitor what you eat and what you do, especially for the first three months I was a nervous wreck.”
Atkinson, who competed on Strictly Come Dancing in 2017, also recalled putting on weight during her stint on the BBC One show.
She said: “I think I’m the only contestant who gained weight during Strictly and I always say that openly because the training is hard, it’s intense.
“But because I train differently anyway, my body kind of went backwards a bit and the main reason was because I let my diet slip massively on Strictly.
“We trained above the Cadbury’s shop, so I had a Toblerone nearly every day, fast food, anything that was just quick and easy really.
“I think I put on about six or seven pounds by the end of it.”
Atkinson and professional dancer Marquez met on the 2017 series of Strictly, when she was partnered with Aljaz Skorjanec and he was dancing with singer Alexandra Burke.
Listen to the full interview on the Women’s Health Going For Goal podcast from August 13.
