If you thought clay was best used to build houses or make pottery, think again. It turns out that it is also being used in detox diets. Yes, really.
The Clay Diet involves stirring edible clay, such as Bentonite, into a glass of water to drink. It isn't a food replacement, but is designed to accompany your regular diet.
The clay is supposed to absorb and remove toxins, impurities and chemicals from the body.
The diet's biggest cheerleader is 'Divergent' actress Shailene Woodley, but other clay users include Zoe Kravitz and Elle Macpherson, according to the MailOnline.
In an interview with Into The Gloss, Shailene explained her penchant for clay: "I've discovered that clay is great for you because your body doesn’t absorb it, and it apparently provides a negative charge, so it bonds to negative isotopes. And, this is crazy: it also helps clean heavy metals out of your body."
Devotees defend their clay choices by saying that it has been ingested by people from across the world for hundreds of years (Shailene first learnt of eating clay from her African taxi driver), but experts say this doesn't necessarily make it advisable.
"This is a practice in some indigenous cultures, and I think that probably came about because they did not have access to certain nutrients in their diet, like calcium from dairy, or iron, and there are some minerals in dirt or clay," explained TODAY Show contributor and gastroenterologist Dr. Roshini Raj.
That said, according to the MailOnline, the clay diet industry is now worth some £2billion and many women claim to have lost a dramatic amount of weight on the diet.
But not everyone is convinced.
There appear to be some serious health warnings around the diet. In 2012, the Food Standards Agency (FSA), advised against ingesting clay - including bentonite.
"Exposure to arsenic can be associated with an increased risk of lung, skin and bladder cancer. Exposure to lead presents a risk for infants and children in particular, as it can be detrimental to brain development and affect intellectual performance. For the same reason, pregnant women are also advised to avoid eating or drinking clay due to the potential risk to their unborn child."
Dr. David L. Katz, a HuffPost blogger and founding director of the Prevention Research Center at Yale University, says that more work needs to be done before the clay diet can be recommended.
"Removing metal from the body is not necessarily good -- iron, for example, is a metal and essential to health. So, there could conceivably be benefits, but there could certainly be harms -- and a favorable benefit/harm ratio has not been established to justify recommending this," he told The Huffington Post.
The NHS and British Dietetic Association take issue with the detox trend as a whole.
There’s no scientific evidence to show that our bodies need help to get rid of waste products – this is what our kidneys do – and there's no proof that detox diets work
The British Dietetic Association has said that “the idea of 'detox’ is a load of nonsense. There are no pills or specific drinks, patches or lotions that can do a magic job."
What do you think of the diet? Let us know in the comments below.