As Charlotte Cosby showed off her super-slim figure in a new Instagram photo, many of her fans balked at her now tiny frame. For the Geordie Shore star, who has lost has lost two and a half stone and four dress sizes over the past year, is looking thinner than ever. In fact, she is looking so thin, that some have questioned whether the 24-year-old actress has taken things too far. Scroll down for video . Over the last year Charlotte Crosby has lost over two and a half stone, but the reality TV star has come under fire for this picture in which she appears to be very slim . One Twitter user commented that she thought Charlotte was 'far to skinny [sic] whilst other commented on her Instagram pictures . One user on Twitter posted a picture of the star with the comment: 'Charlotte Crosby is far to skinny! She's promoting to girls that she has a "healthy body" [sic]' Another commented on her Instagram: 'I can guarantee you she starves herself to look like this.' But Charlotte is not the only Newcastle resident to have lost weight. Her co-stars Vicky Pattison, 27, Holly Hagan, 22, and Marnie Simpson have also all dropped the pounds over the past 12 months. Charlotte has a lost a lot of weight over the last 12 months (left, before the weightloss, and, right, after) , she puts this down to exercise and having cut back on take-aways and booze . Charlotte in 2013 before her weight loss transformation attending the Radio 1 Teen Awards at Wembley . And the women aren't afraid to show off their bodies. Vicky regularly posts then and now pictures of herself to her 1.6million Instagram followers charting her weight loss progress. Holly and Marnie are the same. Sharing pictures of their super slim bodies, often in bikinis or skimpy outfits. But have these girls taken things too far? Well, one doctor thinks they might. Dr PhD Marilyn Glenville told us that there is a lot of pressure on women in the media to try and stay thin. Vicky Pattison regularly posts pictures of herself to Instagram, before (left) and after (right) her weight loss . Marnie Simpson said she felt compelled to lose weight after seeing that her fellow Geordie Shore Castmmates had dropped so many pounds . She said: 'There is too much too much pressure as they are in the public eye and understandably want to look good but it may push them into unhealthy eating patterns in order to achieve that look. 'Because of the pressure the weight loss can be taken too far and too fast as with many of the Geordie Shore girls.' She continued: 'When weight loss is very fast the body is encouraged to lose fat, muscle and water. Water is just a temporary loss and you also do not want to lose muscle. 'And for women it is important not to lose too much fat, because then periods will stop and it can affect not only fertility but also increase the risk of problems like osteoporosis because the woman has lost the protection of the female hormones.' Holly Hagan is the fourth Geordie Shore girl to dramatically lose weight, she had even posted a picture of herself trying out a waist trainer to Instagram (left) Holly posted this picture of herself to Instagram where he ribs are clearly visable . Holly was larger when she started on the show, but, she has since slimmed down after revealing she felt fat . Dr Marilyn also revealed that it is best for fans to stick away from following celebrities in their diets. She said: 'It is better to choose a plan to suit your body and to take into account whether you have a sedentary job or working away from home a lot so can’t control your food easily. 'It will make a difference if you are very stressed and also how old you are because metabolism tends to slow down as we get older. 'It is important that you choose a diet that suits your lifestyle, age and how you want to look so that you don’t end up looking and being too thin or causing health problems.' However two of the girls have hit back at the criticism of their weight. Holly told the BBC: 'What really annoys me is when I read articles and it's like, "Holly lost three stone in one month" and that is giving such a wrong impression to the girls out there reading that and thinking, "Oh yeah I can lose three stone in one month". She continued: 'They just pluck these figures out of thin air, and it shouldn't be allowed to happen because that could have really damaging effects.' Charlotte has also denied losing weight just for her DVD: 'Sadly I just put weight on through loads of partying, drinking, having a boyfriend and eating takeaways every night,' she said. 'I don't know why I would ever want to put weight on and look that fat and ugly. Why would anyone ever want to do that? It's so stupid that people even say that.' Much has been made of just how the Geordie Shore girls, who were famous for their booze and take away heavy diets, have managed to loose so much weight. Here's what they've said... Charlotte Crosby . Charlotte's diet was not the most conventional. As her BFF Vicky revealed that she uses a controversial sounding 'three tin' regime. 'She basically thinks you should eat three tins a day and that's it. So you could have a tin of beans for your breakfast, tin of tuna for your dinner and a tin of pears for your tea,' said Vicky. Charlotte also introduced exercise into her life to beat the bulge. She started working with celebrity trainer Richard Callender and released a number one best selling fitness DVD. Holly (plain yellow bikini) recently posted this picture of her and Charlotte saying that the pair were now proud of their bodies . Holly Hagan . Holly, who recently posted a picture of herself in a Kim Kardashian-style waist trainer to Instagram, trains hard and has lost over a stone and a half. She said: 'I do work hard to maintain my body as I work with a personal trainer 2/3 times a week, and we train really hard together.' She also maintains a calorie-controlled diet and has previously revealed that she prioritises fruit and vegetables over stodgy treats. 'Carrots before carbs,' she explains. 'I've been doing it for so long now that when I eat s*** it makes me feel bad. I prefer to be healthy now.' A typical day for her would be scrambled eggs for breakfast, a chicken salad for lunch, and for dinner, steak and vegetables. Vicky Pattison . Before embarking on her weightloss transformation Vicky survived on a diet of takeaways. Now, she's a svelte size six after insisting that producers provide the reality show stars with a healthier menu - something she says has 'made all the difference'. 'It’s made such a difference,' she says. 'You don’t get much time to cook, so we used to have a crisps cupboard and a chocolate drawer, which we'd descend on like a pack of raccoons after a night out. 'With the catering, we swapped our fry ups for eggs or porridge for breakfast and then salads and meat platters for lunch. That made keeping our figures loads easier.' Vicky also followed the her own Seven Day Slim routine, which she turned into a DVD, which saw her shed three stone over the course of six months. Following her dramatic slim down she was unhappy with the way her breasts looked and had a boob job to plump them back up again. Vicky posts these pictures to her Instagram detailing how she has transformed her body . Marnie Simpson: . Marnie decided to lose weight at the end of last year after becoming jealous of her co-stars slim bodies. She dropped 17lbs - over a stone - in just one month and said: 'A lot of people started to pick up on my weight on Twitter and say some really hurtful comments. 'I remember one person said, "You used to be the skinniest and now you're the fattest." 'Another said, "Your face is huge," because when I do pile on the pounds it always shows up really quickly on my face in the shape of a double chin. 'There were also lots of comments about being be the "fat one" in the show and the "fat lass". 'I'd be lying if I said those comments didn't really hurt - you try to ignore them but it is impossible.' After a month of intensive work-outs and eating healthily, the reality TV star went from 9st 10lbs to a super-slim 8st 7lbs.
Charlotte Crosby was criticised for her slim frame on social media .
The star has lost more than two and a half stone in the past year .
Her Geordie Shore cast mates have also shed the pounds .
A doctor warns that they could be taking their diets too far .