Staring into the camera, Zach Choi loudly munches, slurps, chews and sucks his way through several kilos of wagyu steak and a vat of cheese fondue.

The 33-year-former's video clip lasts around just 10 minutes and since it was posted to his YouTube channel a few weeks ago, information technology's been his almost pop upload to appointment, with nearly 4million fans tuning in to run into and hear every spine-tingling seize with teeth.

With but under 10million subscribers and a staggering 1.5billion views of his videos to date, Zach, who is South Korean-American, is considered the king of a niche group of YouTubers who rake in millions by scoffing vast quantities of food on camera – and making sure they practice it noisily.

This baroque footage, complete with exaggerated eating, is said to trigger a physical sensation that some viewers feel is soothing, while others detect information technology weird merely intensely watchable. However it's not without controversy with claims of animal cruelty and warnings information technology might trigger eating disorders.

A spin-off from the Southward Korean mukbang trend, where people alive-stream themselves gorging on food, this new moving ridge of footage is known as ASMR (democratic sensory meridian response) eating videos, where artists have their craft farther past using two microphones, known every bit binaural recording, to create a 3D stereo sound sensation that makes listeners feel like they're in the aforementioned room.

Such extreme behaviour is a long way from the first intentionally triggering ASMR videos posted in 2009, which featured gentle sounds like whispering and boom tapping.

'The experience, in which audio-visual stimuli trigger a tingling awareness on the scalp and neck along with a country of relaxation and positive mood, is idea to strongly resemble the frisson experience, sometimes referred to as "musical chills" and has some overlap with mindfulness,' explains Dr Emma Grayness, who is known as the ASMR Psychologist and has her own therapy-based YouTube channel.

'The brain regions that are activated accept been shown to be similar to those during social bonding experiences – for example, calmly sitting together, gently touching – and information technology is idea that every bit a issue, ASMR triggers the release of a cocktail of hormones, including oxytocin, sometimes referred to as the "dear" or "trust" hormone. These are responsible for the calming and positive impact it has on people helping them to relax and sleep.'

Its growing popularity, she adds, is down to the power of social media.

'ASMR is thought to predate humans with something similar being observed in the training behaviour of primates,' she explains. 'However its recent boom in popularity is probably due to a number of factors, including how diverse platforms have immune the community to connect and flourish, while offer a stigma-free and accessible manner for people to gain back up and relief from their mental health problems, including indisposition, anxiety, stress and depression.'

When it comes to understanding how eating food can exist considered soothing, the ASMR Psychologist explains that while nosotros're still at the very beginning of learning about the bear upon, the triggers seem to mimic early experiences of being cared for.

'For example, beingness whispered or spoken to softly,' she says. 'In these videos an of import aspect are mouth sounds, something that you lot are more probable to hear if y'all are very close or connected to someone as they care for you lot, this is why creators use very sensitive microphones.'

The ASMR psychologist hold a lit match and a glass bottle full of coloured matches

ASMR is idea to predate humans with something like being observed in the training behaviour of primates,' explains Dr Grayness, who is known as the ASMR Psychologist.

With ASMR nutrient videos at present being viewed billions of times across the globe, the most successful YouTubers – known as ASMRtists, tin can earn lucrative total-fourth dimension incomes through ads, chapter links and brand deals. Social media data analyst visitor Social Blade estimates United states-based Zach Choi earns a tasty £150,000 – £2.4million a year, while Canadian Naomi MacRae, aka Hunnibee, has racked upwards 4.3million subscribers, 690million views and earns equally much as £165,000 a calendar month past eating vast trays of fast nutrient, sweets and 'edible objects' similar hairbrushes.

If farther proof of ASMRtist clout was needed, merely last summertime, American chocolate company Reese even released a video on social media, featuring popular YouTubers, such as ASMR Darling and Matty Tingles, sitting around a table and gently talking into headsets about the joys of eating one of their nigh famous products, peanut butter cups. So far the lxxx-infinitesimal long film has been viewed over 650,000 times.

Of course, in an ever expanding genre where binge eating and whispering betwixt bites are common features of the videos, private YouTubers take learned to develop their ain unique styles to win fans.

The USP of hugely popular British Youtuber ASMR Mag UK is to bake hyper-realistic cake replicas of fast food and everyday objects like mobile phones. Then, wearing her signature glossy lipstick and her confront half-concealed, she loudly munches her way through the lot, whispering betwixt bites. In merely a year, she'due south attracted 100K subscribers and 5.8million views, with estimated earnings of up to £46,000 a twelvemonth.

Like many of her peers, the mum-of-one's identity is kept secret. Known simply as Mag, she describes herself equally 'a sassy black British lady based in London'.

Her success, she explains, is down to difficult work and '4 hours sleep a night', as Mag runs her ASMR career alongside a full-time task. She adds that the whole idea just came about considering she wanted to heighten coin for clemency.

'I had read an article about orphans and decided to make extra income to assist orphanages around the world,' she explains. 'Being a female parent of a two-twelvemonth-old, I couldn't sit back and do nothing.'

A self-taught baker, each of Magazine's edibles takes four days to test and perfect, and she invites her fans – or Royals, every bit she calls them – to help choose each video's theme.

'Buying sweets and treats from the shop only seemed too uncomplicated, easy and lazy, ' she admits. 'I wanted my channel to be something special where anyone who watched my videos would get a sense of how much endeavour and love went into my creation, giving them new exciting experiences in every video. When I started receiving compliments nearly how realistic and satisfying my ASMR was and how they made people feel condom and special, I knew I fabricated the right decision.

'Plus, I have such a busy life and when creating my videos I can be still,' she adds.

However, not everyone is a fan of the ASMR phenomenon.

In April, South Korean YouTuber Ssoyoung sparked outrage when she videoed herself chomping on alive squid, fluctuant tentacles and all. Beau YouTubers accused her of torturing animals.

ASMR video still

South Korean YouTuber Ssoyoung (Picture: YouTube/Ssoyoung)

Meanwhile, another darker, more than unsafe side to the genre's triggers is also beingness called out.

Mattias Strand, a senior consultant psychiatrist from the Stockholm Center for Eating Disorders, has recently conducted the first ever study into mukbang and eating disorders and establish that such videos could exist 'a destructive force' for those more than prone to eating disorders.

'We found that watching mukbang could certainly be problematic for people who already suffer from disordered eating, in that it could trigger binge eating or serve as an inspiration for eating too little,' he explains.

'Some people seem to keep coming dorsum for more and some of them probably have their own bug around eating.'

According to mental health expert Carolina Mountford, at that place'due south definitely growing business about the potential trail of devastation ASMR eating could leave in its wake.

'The food consumed is nigh always fried craven, pizza and vast amounts of noodles and we know that over a sustained period of time, such nutritional choices can lead to heart disease and type 2 diabetes,' she explains.

Carolina Moutford

'ASMR eating glamorises portion sizes that are considerably bigger than what can be thought as reasonable,' says mental health proficient Carolina Moutford.

'Furthermore, mukbang and ASMR eating glamorises portion sizes that are considerably bigger than what tin can be thought as reasonable. For people with disordered eating, watching someone "feast" on (self) restricted foods can easily trigger someone to binge and possibly purge. Evidence shows that restricting foods causes people to captivate over those "prohibited" foods.'

Becky, a Hong Kong-based YouTuber who started her aqueduct Pikki.ASMR eight months ago, also understands concerns about the impact her videos may have on viewers.

To combat criticism, she tries to include fruit and vegetables alongside fast food, sweets and confectionery. And, she says, she stops eating when she's full.  Just what about her fellow ASMR YouTubers who eat then much in their videos? 'I do wonder almost that,' she admits. 'Maybe they only swallow one repast a day?'

Becky says that despite the fact she measures her eating, she yet worries well-nigh her health.

Not only are her meals hugely calorific, just she has to record her videos late at dark to avert daytime noises like traffic and birdsong, which means eating a huge amount of food that includes buffalo wings, chicken nuggets and doner kebabs later 10pm three times a week.

'It's really likewise tardily at night,' she admits, but adds that having recently striking the crucial 1,000 subscribers needed to beginning earning coin from her videos, she isn't prepare to requite up just yet. 'I think I will give it at least one more twelvemonth,' she says. 'I'd similar to earn a stable income.'

While a recent obesity surge in South Korea has caused worried health officials to suggest mukbang might need government regulation, here in the Great britain, ASMR fan Yolly Littleboy explains that while the videos she watches practise have an affect on how she eats, for her, information technology'due south a positive one.

The xix-year-old medical pupil from Bournemouth has a sugariness tooth and says that watching someone else eat chocolate and cake helps curb her ain cravings for sugary foods. 'It's satisfying but to sentry someone else eat that stuff,' she explains.

Yolly offset became aware of ASMR food videos during lockdown. Sometimes just listens to them considering they help her fall asleep. 'They make me feel then relaxed,' she says.

Mental health expert Carolina insists that whatever positives linked to ASMR videos are far outweighed by the negatives of watching them.

'At all-time, this phenomenon risks promoting poor habits and overeating,' she says. 'At worst, it can contribute to the rising numbers of individuals with eating disorders, which are serious psychiatric illnesses, as well as significantly hampering the recovery of those who are trying to get better.'

Withal, the ASMR Psychologist is adamant at that place is no connection.

'An eating disorder is the issue of an individual's struggle to manage strong negative emotions triggered by low cocky esteem,' she explains. 'Information technology is not the result of nutrient or eating. Videos that feature these things – even something similar a cooking tutorial – may make an individual with an eating disorder feel uncomfortable every bit they remind them of their affliction, and as a result they may choose non to lookout them.

'But these type of nutrient videos themselves simply do not pose a risk to those with eating disorders.

'ASMR triggers are very individual, personal and varied in the same way that early experiences of being cared for are,' she adds. 'And then for some people they can actually help bargain with mental wellness issues, non crusade them.'

MORE : The rise of the mukbanger: Why more people than e'er are watching strangers stuff their faces in lockdown

MORE : YouTuber defends eating v,000 calories a day in mukbang diet to shocked Phillip Schofield on This Morning: 'Information technology's not sexual'

More : Meet Gainer Bull, the 500lb erotic weight gainer eating 10k calories a mean solar day to delight his OnlyFans followers