Amanda Seyfried has apologised for targeting ''semi-influencer'' Arielle Charnas in a body positivity debate.

The 'Mean Girls' actress has been embroiled in a social media row with the blogger this week after she claimed she was ''glorifying an unhealthy body image'' by showing off her very slim frame in a bikini snap.

After the pair clashed over the debate - including the suggestion Arielle, 32, only achieved her body because she had nannies meaning she could spent more time at the gym - Amanda, 33, posted on Instagram: ''All who feel bullied or thin-shamed during our recent social media discussion.

''If you know me or are familiar with any of my beliefs or stances you'll recognize that it isn't in my character to tear down anyone for 'being who they are.'

''As I'm acutely aware, there's a price tag for the group of people who find themselves with a platform to stand on.

''You have to be aware of the message you're sending and be able to back it up when faced with criticism (not just praise). Hold yourselves accountable instead of using the terms above.(sic)''''

Although she stood by her opinions on the issue, Amanda admitted she was wrong to target Arielle and ''tear'' her apart.

She added: ''The only thing I'd take back is exactly how I started this debate. I desperately wish it hadn't targeted (or blasted) one person (there are MANY who engage in this questionable messaging) and instead started a cleaner, general conversation.

''No one needs to tear anyone apart. And I regret that it's present right now. To the lady in question: I'm sorry for the truly negative feels you've endured because of this.''

The 'Jennifer's Body' star's apology came after Arielle shrugged off the criticism and branded it ''BS''.

She wrote: ''[It] has nothing to do with my body and for random women to tell me I should be crediting [the nannies] for my figure and my 'excessive workouts' is actually disgusting.

''So sad that women who are so unhappy just feel the need to continuously put other women down when all they do is preach about female support. It's BS and I'm sick of it.''