Images promoting potentially life-threatening eating disorders are thriving on Instagram and need to be cracked down on in the same way as graphic self-harm images, leading charities and experts have said.

The social media giant’s focus on removing graphic images of self-harm did not go far enough, they said, and young people also faced being confronted with pro-anorexia images due to little policing on the site.

The Guardian has discovered thousands of hashtags and accounts promoting anorexia, including diaries of weight loss, alarming pictures and comments on goal weights.

These accounts often include a comment saying: “Please don’t report, just block,” to circumvent the website’s approach, which requires people to report content that they find worrying.

The director of external affairs for the eating disorder charity Beat said content promoting anorexia and bulimia was prevalent online. “So-called pro-ana and pro-mia content is widespread on social media and can be very harmful for people suffering from an eating disorder,” Tom Quinn said. “People will not develop an eating disorder by being exposed to images that glamorise eating disorders, but research shows that such content helps perpetuate the illnesses for people who are already suffering.

“We welcome Instagram’s recent increases in its security measures to protect users from content that promotes eating disorders. However, social media platforms should do more to ensure such content cannot be posted in the same way as Instagram is now cracking down on images of self-harm.”

Dasha Nicholls, the chair of the eating disorders faculty at the Royal College of Psychiatrists, said some people on sites such as Instagram were using the platform to “actively promote disordered eating and inspire others to behave in that way, particularly around restriction and fasting”.

She said: “We have to take down graphic images of eating disorders … There is good evidence those most vulnerable are likely to access those sorts of sites. There is a social obligation and whether there is also an industry obligation is an important point that is coming out at the moment as well.”

Ursula Philpot, a dietitian at the British Dietetic Association, said she fully supported a crackdown on pro-anorexia content on Instagram.

The calls come after Instagram announced that it would ban all graphic self-harm images as part of a series of changes made in response to the death of the British teenager Molly Russell. The photo-sharing platform made the decision after being met with a tide of public anger over the suicide of the 14-year-old girl, whose Instagram account contained distressing material about depression and suicide.

But experts have said that confronting graphic self-harm imagery alone does not go far enough, and Instagram also needs to look at other pictures that could put vulnerable users at risk.

Jennifer Grygiel, a social media expert and assistant professor of communications at Syracuse University, said: “Instagram has attracted a community focused on anorexia that at times can promote the practice, which could lead to increased health risks including self-harm.

“Instagram specifically needs to increase their attention in moderating this content to make sure that using the platform does not increase associated health risks, especially among teenagers and youth who are heavy users.”

Many accounts encouraging eating disorders are private and tell people to follow them to access the content. But other images are openly searchable. While Instagram banned some high-risk search terms in 2012, there are workarounds that make it easy for users to find images without any link offering support or asking people whether they want to continue to the content.

Jade, 19, has experienced an eating disorder since she was 11. “When my eating disorder and depression were at their worst, I scoured apps like Instagram to find these images which only worsened my self-image. At this time the posts were few and far between. Clearly the amount of images is now vast across almost all social media platforms,” she said.

She added: “Also due to the romanticism of the posts, I believed that it was completely normal to starve myself and engage in other self-harming behaviours. It isn’t only Instagram that is riddled with these potentially distressing images, sites or apps like Tumblr, Pinterest and Weheartit are also full of these posts.”

Laura, 22, from North Yorkshire, said: “I have an eating disorder myself. I have an Instagram account and there is a serious amount of triggering content that is not being dealt with and it’s very easily searchable.

“On other apps I have been on there are even anorexia coaches, so people who will tell you what to eat and if you don’t eat a certain amount of food, which will be hardly anything, they will say ‘you have to do this to yourself’.”

Instagram’s focus on images of cutting is based on recent reviews carried out with experts who viewed them as holding the biggest potential to unintentionally promote self-harm. The company is understood to be continuing to review its policies.