The actress, who also appeared briefly in Coronation Street, told RTE that she is "fairly relaxed" with her body.
"I do know people in my industry who put a lot of pressure on themselves. More about diet than fitness, funnily enough," she said. "I've never heard of someone overly working out, I usually hear of people not eating carbs. I've never done that, I've never done any sort of extreme dieting.
"It's silly pushing yourself, everyone's got their own body shape and you can do the best with that or the worst with that."
Amy added that she does not understand why people strive to look like celebrities.
"There's no point in somebody looking at Cheryl Cole and going 'I want her body' because you've got your own body and you can look after it as well as you want, but you can only work with the shape that you've got," she said.
The 29-year-old, who is currently dating Irish rugby player Rob Kearney, also insisted that dieting is not one of her priorities.
"Providing you're healthy and you're doing what you can, I think that it's important that people feel that they don't have to look ridiculously skinny," she said.
"It's not a look that I think is particularly nice anyway and it's just good to stay in shape, be healthy and eat properly. Maybe I do eat too much sugar and all that I could improve on some things. I'm definitely not perfect in my diet but it's only so important."