New Device Aimed at Curbing Obesity Criticized for Being Dangerous, Fatphobic

A photo of the DentalSlim Diet Control device.

University of Otago

Key Takeaways

  • A new device that was designed to help people lose weight is facing backlash, as experts say that it is medically unsound and harmful.
  • The DentalSlim Diet Control device uses magnets on the wearer’s back teeth to restrict the mouth’s ability to fully open. With limited jaw mobility, people wearing the device must adhere to a liquid diet.
  • Experts say that the device is dangerous and puts people at risk of developing disordered eating.

A new device designed to help people lose weight is drawing sharp criticism for being harmful and misrepresenting the cause and treatment for obesity, all while promoting fatphobia. 

Researchers from the University of Otago in New Zealand and the United Kingdom have developed a device called the DentalSlim Diet Control that is fitted by a dentist and uses magnets and bolts to limit the opening of the jaw to about 2 millimeters.

The device facilitates weight loss because the wearer's ability to open their mouth is restricted, and they must rely on a liquid diet.

In a statement from the University of Otago, lead researcher Professor Paul Brunton said that the DentalSlim Diet Control device is an effective, safe, and affordable tool for people with obesity.

However, the device has received ample criticism for being not only medically unsound but having the potential to lead wearers down a path to disordered eating.

A paper published by the researchers found that a handful of participants who took part in the research on the DentalSlim Diet Control "only occasionally" felt tense and embarrassed by the device, and said that life was less satisfying while wearing it.

Twitter Backlash

In the statement, Brunton said that “the main barrier for people for successful weight loss is compliance and this helps them establish new habits, allowing them to comply with a low-calorie diet for a period of time. It really kick-starts the process."

According to Brunton, the device "is a non-invasive, reversible, economical and attractive alternative to surgical procedures.”

However, not everyone agrees. In response to the university’s tweet sharing the invention’s press release, many people online called the design a “torture device” and said it was fatphobic.

Others asked how patients would be able to throw up if they got sick, comparing the device to the practice of jaw wiring for weight loss (an outdated practice where people’s jaws are wired shut, preventing them from eating).

“Touted as a positive step in the ‘war against obesity,’ I join my colleagues all around the world in saying this is a dangerous, damaging, and barbaric tool,” Anita Federici, PhD, the clinical director at the Centre for Psychology and Emotion Regulation and a fellow at the Academy for Eating Disorders, tells Verywell.

Federici adds that the development of the device and the researchers' defense of it "demonstrate a gross lack of understanding of weight science, fat-shaming and eating disorders.”

Limiting Food Does Not Treat Obesity

Experts say that one of the major flaws of the DentalSlim Diet Control device is that it purports to help combat obesity—but food restriction does not work for weight loss. Eating nourishing foods promotes health, but dieting does not deliver long-term results.  

Amanda Raffoul

A device like this reiterates messaging that oversimplifies the science around weight and the science around eating patterns.

— Amanda Raffoul

Amanda Raffoul, a postdoctoral researcher at the Strategic Training Initiative for the Prevention of Eating Disorders at the Harvard T.H. Chan School of Public Health and Boston Children’s Hospital, tells Verywell that the cultural—and often medical—narrative that weight is managed by modifying what you eat and how much you exercise is wrong. 

Instead, Raffoul says that science has shown us that genetics, along with biological, psychological, and societal factors, influence someone’s body weight. In other words, dieting or overexercising will not fundamentally change the way your body is designed to be. 

“A device like this reiterates messaging that oversimplifies the science around weight and the science around eating patterns,” says Raffoul.

Regaining After Restriction

Terri Marques, the executive director at Bellwood Health Services in Toronto, tells Verywell that research has shown that when someone goes on a diet or weight-loss program, “about 95%” of weight loss is gained back quite quickly.

“The body has a tremendous ability to defend the weight that it wants to be at,” says Marques. In fact, a systematic review on weight loss programs found that 12 months after the diet began, the effects on weight reduction largely disappeared.

“It is not uncommon for individuals to just go on to the next weight loss program and accept that it was them who failed at weight loss; that they did not have enough willpower," says Marques. "They rarely question the efficacy of the weight loss device or program."

Terri Marques

The body has a tremendous ability to defend the weight that it wants to be at.

— Terri Marques

Instead, Marques says that the body needs the right nourishment consisting of carbohydrates, protein, and fat to function. Denying the body the fuel that it requires to survive through a liquid diet is not consistent with normalized eating. 

Even the researchers behind the DentalSlim Diet Control study found that two weeks following the device’s removal, all the participants gained back weight. Federici believes that the very nature of the research is problematic, as demonstrated by its incredibly small sample size of seven, along with its ill-informed positions around obesity. 

Perpetuating Harmful—and False—Obesity Narratives

Federici, who specializes in eating disorders, says that despite the science of weight and biology, the creators of the device purport that calorie restriction "should be successful,” but also claim that the effects are negligible or only successful in the short-term because of “poor motivation” and not sticking to lifestyle changes.  

Anita Federici, PhD

An inability to keep weight off or change one's body weight has nothing to do with your motivation or your personality.

— Anita Federici, PhD

In their paper, the authors also wrote that people with obesity “usually have an addictive personality and an impulsivity for sugary food” and suffer from binge-eating disorders.

“It is appalling to see a statement like this in 2021," says Federici. "I want every reader to know that an inability to keep weight off or change one's body weight has nothing to do with your motivation or your personality."

“The outcome of being on a low-calorie diet, for the vast majority of people, is going to be a strong biological drive to eat," says Federici. "That isn't impulsivity, that is the impact of starvation and is well documented in research trials.”

A Holistic Approach to Obesity

Vijaya Surampudi, MD, an assistant professor of medicine in the Division of Human Nutrition at UCLA who works in the Center of Obesity and Metabolic Health, tells Verywell that treating obesity is about much more than restricting calories.

There are a lot of environmental, psychosocial, genetic, and hormonal factors that play a role in someone’s body size, which means that a holistic approach is needed.

“The most effective treatment of obesity is a wellness journey and it is a long-term process of lifestyle changes,” says Surampudi. “We all need support in making lifestyle changes, so finding healthcare professionals to help you on the journey will be essential.”

How Diets and Harmful Devices Affect Eating Disorders

Weight discrimination is prevalent in our day-to-day lives. Consumers are bombarded with “tummy flattening” teas, waist trainers, dieting apps, and exercise programs that focus only on weight loss instead of overall health. Experts say that these weight loss practices are not only unsustainable but that they can also lead to disordered eating or an eating disorder.

Raffoul says that an early sign or risk factor for an eating disorder is a pattern of dieting. A device that promotes weight loss, like the DentalSlim Diet Control, will initially cause a change in weight because people are not eating. 

“But what happens is that again, when somebody starts eating food, they will inevitably gain the weight back,” says Raffoul. “And that dissatisfaction with one's body, and that period of weight cycling, actually increases the risk of developing an eating disorder later on.”

Federici says that it’s important to note that approximately 30% of people in larger bodies have Binge Eating Disorder (BED). What's more, stigma, bias, and a lack of accurate information, mean that many people with BED do not actually know that they have an eating disorder.

“When they seek help, they end up in weight loss clinics and bariatric surgery consultations,” says Federici.“They rarely get assessed or treated by eating disorder professionals, who have strong evidence-based treatments for binge eating."

The DentalSlim Diet Control device is intended for people with obesity—some of who might have BED, even if they are unaware of it. To Federici, it's "horrifying" to think that "some of the people who will be targeted for this device will be those who have eating disorders."

What This Means For You

A new device that was designed to treat obesity is facing criticism online for promoting dangerous eating habits. Experts say that the device, which uses magnets to limit the movement of the jaw, is not medically useful and could lead to someone developing disordered eating.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. The University of Otago. Researchers develop world-first weight loss device. June 28, 2021.

  2. Brunton P, Ratnayake J, Bodansky H, et al. An intraoral device for weight loss: initial clinical findings. Br Dent J (2021). doi:10.1038/s41415-021-3081-1

  3. Ge L, Sadeghirad B, Ball GDC, et al. Comparison of dietary macronutrient patterns of 14 popular named dietary programmes for weight and cardiovascular risk factor reduction in adults: systematic review and network meta-analysis of randomised trialsBMJ. 2020;369. doi:10.1136/bmj.m696 

By Laura Hensley
Laura Hensley is an award-winning lifestyle journalist who has worked in some of the largest newsrooms in Canada.