The Lenny Bikini Show at Rio de Janeiro Fashion Week proved that thin doesn’t mean healthy as one model’s buttocks seemed to be lacking in muscle tone – which some industry insiders say could be the result of skipping workouts and staying slim by eating very little.

“It’s no secret that a bad diet, little rest, no exercise, caffeine and smoking is not good for our bodies,” said Sheldon Stringer, personal trainer and owner of Urban Fitness Islington in London.

“The main cause of cellulite is simple: a bad diet of fatty foods married with long periods of not eating and dehydration or lack of water intake.

“A lot of people also rely on other stimulants and sometimes even substitute food and water for these stimulants. This will also lead to diminished muscle tone and also promotes the development of cellulite.

The Lenny Bikini Show at Rio de Janeiro Fashion Week proved that thin doesn’t mean healthy as one model’s buttocks seemed to be lacking in muscle tone

“In the case of these models, the stress of having to look their best, not eating to try and remain slim and working long hours with little or no rest, will result in cellulite build up as seen in these pictures.

“Due to the lack of nourishment caused by their bad diets and their intense schedules, their muscle mass is compromised as their bodies are starving most of the time, which results in flabby or flat muscles.”

The new images of Rio de Janeiro Fashion Week models come in the wake of revelations that models stay “Paris thin” by eating tissues and outrage caused by River Island’s use of what seemed to be a size zero model in its latest campaign.

The tissue allegations appeared in the memoirs of veteran fashion journalist Kirstie Clements, who was sacked from her role as editor of Australian Vogue in May 2012.

Kirstie Clements claimed she once spent three days on a shoot with a model but didn’t see her eat a single meal.

By the end of the trip, said Kirstie Clements, the model was so exhausted and weak from lack of food, she could barely keep her eyes open.

The fashion journalist also revealed that many starve themselves for days on end, endure regular stints on hospital drips and eat tissue paper in order to feel full.

“You know how you read interviews where models insist that they eat a lot? Not true,” said Kirstie Clements.

“The only way they can get that thin is to stop eating. They eat tissue paper to stave off the hunger pangs – literally ball it up and eat it.”