Image copyright India Benjamin Image caption India got hooked on diet tea while at uni

India Benjamin had never heard of diet tea before she saw people she followed on social media promoting it online.

"Everyone I seemed to be following - the skinny bronzed girls - were all just flogging it at the time," the 26-year-old tells Newsbeat.

She tried a diet tea which uses laxatives when she was at university to try to balance her unhealthy student lifestyle.

But India had previously struggled with eating disorders and says her use of diet tea became an addiction.

Doctors say using laxatives can be "dangerous" and shouldn't be considered as part of a weight loss plan.

"It changes how a gut works, it changes the gut bacteria that we know now is very important to maintaining our health," said Dr Duane Mellor, senior lecturer in human nutrition at Coventry University.

And there's "no scientific evidence" to back up claims that herbs in diet teas have weight loss benefits, according to nutritional therapist Sonal Shah.

India's experience was several years ago, but diet teas - and the celebrities who promote it - have come under harsh criticism this week from actress and activist, Jameela Jamil.

Image copyright Getty Images Image caption Jameela Jamil hit out at several stars on Twitter, including Cardi B and Iggy Azalea

"If you tell your fans to be thinner, you don't love your fans," she tweeted.

Jameela targeted Cardi B, Iggy Azalea, Khloe Kardashian and Amber Rose for recently promoting weight loss products to fans.

She says people who are paid for these sponsored posts don't care about fans' "mental health or self worth".

Image copyright Jameela Jamil / Twitter

In a video watched by 10.1 million people, Cardi says she used the tea to suppress her appetite and planned to continue to use the tea when she ate fattening foods.

And Iggy Azalea said a brand of tea helped define her stomach without losing weight from other parts of her body.

'I was addicted to feeling thinner'

Image copyright India Benjamin Image caption India convinced herself she had IBS when she was suffering from bowel problems caused by over-use of diet tea

Many brands, including the one Cardi B advertised and leading UK diet teas, don't use laxative herb senna in their products - but it was the effects of senna that caused problems for India.

"You take them and lose a little bit of bloating, but when you've had an eating disorder you get addicted to feeling thinner and they do help in the short term," she says.

India says drinking the tea "completely messed up my bowels" after drinking several cups a day in a six-month period.

Most brands recommend drinking much less over a very short time period.

When the cost started to build, India ditched the branded teas and started drinking cheaper senna teas, which can still be bought from high street health stores for as little as £2.49 a box.

Image copyright India Benjamin Image caption India says she only realised she had a problem with diet tea when her boyfriend made a joke about her being addicted to them

She believes drinking diet teas can be useful for someone feeling bloated and says that friends of her who use it experience no problems.

"I've got a couple of friends who still do them occasionally, like if they've had a really indulgent week, but it's only really me who got a bit crazy on them," she says.

"But that's because I'm the only one of us who's had an eating disorder in the past."

'I lost my appetite - and gave myself an ulcer'

Image copyright Queenette Konyeha

23-year-old Queenette Konyeha tells Newsbeat she developed an ulcer and a bladder infection after using products she'd seen celebrities promote on Instagram.

"You want to try it because you feel that they use the product and it works for them so it will actually work for me too," Queenette says.

"But I got an ulcer from using it because I wasn't eating properly anymore. It made me lose my appetite."

Queenette now uses other natural remedies and exercise to lose weight - the method recommended by experts.

"Diet teas aren't sustainable," says Nutritionist-Resource member Sonal Shah.

"If they were, then everyone would be looking slim and healthy. It has to be a whole lifestyle change and it's got to be something that is sustainable."

Image copyright Getty Images Image caption Diet teas are made from a mix of herbs, some of which can have suppress appetite or have a laxative effect

But many diet teas on the market, as Jameela suggested when talking about Cardi B, contain laxatives, which some people use as a quick way of losing weight.

Newsbeat has asked the brand Cardi B is promoting for a statement on Jameela's comments and their products, but they have not responded.

We've also contacted UK-based brands of diet teas for comment, but have not heard back.

Diet tea can 'distort' how we understand food and our bodies

Experts say celebrities promoting diet teas on social media can lead to their followers developing a poor relationship with food from an early age.

"Young people, particularly young girls - many of them don't need to lose weight - start on a weight loss dieting cycle at an early age," says Dr Duane Mellor, senior lecturer in human nutrition at Coventry University.

He says the use of senna-based products "potentially could lead to other uses of laxatives or even purging behaviour, which is very unhealthy."

"It distorts all that natural way we should enjoy food and get to understand how food affects our bodies."

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