Instagram has announced that tighter restrictions are to be imposed on some posts related to diet products and cosmetic surgery.

The social media platform said that from Wednesday on both Instagram and Facebook, age restrictions would be applied to some such posts while others would be removed.

Concerns have been raised about the impact that diet, detox and cosmetic surgery content can have on young people, their mental health and body image.

Instagram said that under its new rules, posts that promote the use of certain weight-loss products or cosmetic procedures, which have an incentive to buy or include a price, will be hidden from users known to be under 18.

In addition, the platform said any content that made a “miraculous” claim about a diet or weight-loss product and was linked to a commercial offer such as a discount code, would now be removed from Instagram.

Emma Collins, Instagram’s public policy manager said: “We want Instagram to be a positive place for everyone that uses it and this policy is part of our ongoing work to reduce the pressure that people can sometimes feel as a result of social media.

“We’ve sought guidance from external experts, including Dr Ysabel Gerrard in the UK, to make sure any steps to restrict and remove this content will have a positive impact on our community of over 1 billion people around the world – whilst ensuring Instagram remains a platform for expression and discussion.”

Jameela Jamil: ‘This is a huge win for our ongoing fight against the diet/detox industry.’ Photograph: Astrid Stawiarz/Getty Images for NYFW: The Shows

Actor and body positivity campaigner Jameela Jamil, who has repeatedly criticised high-profile online figures including Khloé Kardashian for posting on social media about diet products, said the update was a victory for mental health advocates.

“This is a huge win for our ongoing fight against the diet/detox industry,” she said. “Facebook and Instagram taking a stand to protect the physical and mental health of people online sends an important message out to the world.

“I’m thrilled to have been able to work towards this with them, alongside a host of other experts who shed light on the danger of these products.

“Instagram were supportive and helpful when I brought them my protests and petitions; they listened, they cared, they moved so efficiently, and communicated with us throughout the process.”

The Good Place actor started the I Weigh movement and a related account on Instagram in response to the amount of content she felt was promoting unhealthy lifestyles and diet products, suggesting society was measuring success based on weight.

The account encouraged people to share their achievements regardless of their body shape and has since gained more than 830,000 followers.

“As someone who struggled with an eating disorder for most of my youth, I’ve personally known and suffered the perils of the devious side of the diet and detox industry,” she said.

“A focus of our advocacy since inception, it is a proud day for I Weigh and a day of hope for our generation, who deserve respect and protection from the celebrities and influencers that they follow.”