If you are struggling with any of the issues raised in this story, please contact the eating disorders charity b-eat on 0808 801 0677.
Jennifer*, a 16-year-old from the UK, says it took about five months to notice her body odour was changing. "I'd definitely say my body odour was stronger, smelled worse, and came on faster than when I was eating normally," she says. According to her, she began to smell "fishy".
"There was a time a couple weeks ago when I was eating 1000+ calories a day and noticed there was less odour," Jennifer explains. "It started to get way worse when I started to restrict heavily again."
Anorexia nervosa might not be an illness you associate with smell, and yet forums such as My Pro Ana and Something Fishy host countless threads dedicated to unravelling the causes and disguises for anorexia-induced body odour. One user describes the smell as "a mix of rotten eggs and ammonia." Another describes it as something similar to "baby powder or play-doh".
So what's going on here? There is no universally agreed upon diagnosis, but Sydney-based dietitian Lyndi Cohen explains that it's most likely a byproduct of the starving body's "cannibalisation" process.
"Some people with anorexia nervosa are consuming a seriously low calorie diet, around 200-300 calories a day, and their bodies are eating themselves to stay alive. This results in an imbalance in their systems, and a more pungent body odour could be a byproduct of that."
She points out that the body has a range of olfactory ways of signalling an internal imbalance, such as when smelly urine reflects diet or disease.
"This is no different to when you start restricting your food intake for lengths at a time," she says. "It'll make you smell a bit funny because everything has been thrown off balance."
And then there's the fact that people who aren't eating enough don't have the energy to process toxins in a normal way.
"The body still needs to get rid of the toxins in some way or another, and the pores can be one way. This is seen quite often in people who are fluid restricting. This means they start sweating more which might be the cause of the smell".
The noticeable change in odour for someone with anorexia nervosa isn't only physical. Cohen explains that because so much of the illness is psychological, worsening body odour often prompts only more paranoia or self consciousness.
"This type of paranoia could stop them going out in public or socially isolating themselves. From a psychological standpoint, it's quite a tricky thing to navigate".
This feedback loop is reflected in comments thrown around discussion forums, where a lot of users swap tips on concealing the issue with deodorants and perfumes. They also mention their fear of others noticing.
As Jennifer explains, she hasn't been the only one to observe her changing smell. "At first it was just me who was noticing it, but then my family started to comment. They've been really gentle about it though".
Unlike some of the more common symptoms of the disorder, this isn't something that is likely to be picked up on or reported to health practitioners. Cohen thinks this may be because patients aren't comfortable talking about it with their doctors.
"I think one of the reasons they use these forums to talk about it is because it's anonymous and see it as a safe place to discuss things like this".
If you are struggling with any of the issues raised in this story, please contact the Butterfly foundation for eating disorders on 1800 33 4673 or call Lifeline on 13 11 14. A listing of similar helplines in other countries can be found here.
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*Name changed to protect the anonymity of an underage person.