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The SMART device for weight loss: jaw wiring for the 21st century?

Friday, June 19, 2009 Posted by Peter Janiszewski, PhD

For some time, jaw wiring, which severely limits ingestion of solid food whilst allowing for somewhat normal ability to speak, was touted as the panacea for obesity. The procedure was performed by orthodontists, and predictably led to weight loss in many obese individuals (not being able to eat will do that to you). Unfortunately, as soon as the ‘wiring’ was removed, the large majority of patients gain all their weight back – probably not surprising given that no actual counseling on proper dietary patterns, or physical activity were ever prescribed along with the 'wires'.

While jaw wiring seems to have gone out of fashion, a new gadget is entering the market which works in a similar way. The SMART (Sensor Monitored Alimentary Restriction Therapy) device is manufactured by Scientific Intake of Atlanta, US. While the full name of the device sure sounds impressive – don’t be fooled – it is nothing more than a tricked out retainer.

According to the Scientific Intake website, the SMART device does the following:

- It makes you take smaller bites, slowing food intake.
- It requires more chewing of food before swallowing.
- It makes “gulping” of food difficult.
- By slowing the eating process, it permits more appreciation (savoring) of the taste, smell, and texture of food.
- By slowing food intake, it permits triggering of your body’s physiological satiety response when you have eaten less food.

The whole notion behind the product is that if you make eating more difficult and laboured people are less likely to overeat. In fact, it is true that some satiety signals lag behind such that if you eat too fast, you may over-consume before your body signals that you have eaten more than is necessary. For this reason, masticating your food slowly has been often recommended to increase the sensation of fullness at an earlier caloric intake. This method has come to be called Fletcherizing, after a health guru of the past (Horace Fletcher) who recommended that each piece of food much be chewed 100 times - a tad extreme.

Indeed, some recent research suggests that slower eating may reduce energy intake among men, but oddly enough, not women.

So rather than learning to eat food at an appropriate pace, or employing dietary strategies to keep intense hunger at bay (i.e. having a protein-rich snack 15 minutes before having a big meal to ‘spoil your appetite’), you can now insert an awkward piece of plastic in your mouth and do your best not to swallow it along with the food you are consuming.

Now, I must commend Scientific Intake for actually providing some research on which this device is based – this is not often done by other companies peddling weight-loss gimmicks. While the website lists a bunch of supporting ‘studies’, many of these are just poster presentations at conferences (not exactly peer-reviewed literature). However, there was one study conducted on a retainer-type device at the prestigious Pennington Biomedical Research Center which was actually published in the journal Obesity Research.

In short, the study showed that compared to a control day (no retainer), individuals wearing the retainer device consumed approximately 500kcals less.

However, there are some caveats to this study:

1. Only two days were assessed: Day 1) no retainer, Day 2) retainer. Thus, we have no idea what happens in the longer term – maybe people become better at eating more and faster once they become accommodated to the awkward sensation of eating with a retainer.

2. As an extension of point #1, there is no peer-reviewed evidence to suggest that this device will result in significant weight loss. My guess is that when people get really hungry – which they will, being in a constant caloric deficit, they will likely dispense with the device and binge.

3. The participants were MADE to wear the device during all meals. This is very different from having the option to do so in a real life setting. A study of this type – an effectiveness study – where subjects are given the device and allowed to go about their normal routine is required before it can be said whether it will actually work for the majority of people.

4. The duration of the meal intake was not measured – sort of a key variable given the thinking behind the device.

5. As clearly stated by the authors of the study,

Further controlled research, e.g., a clinical trial, will be required to empirically determine the long-term efficacy of the DDS System. Until such studies are performed, the findings of this study should be viewed as a preliminary "proof of concept" investigation.”

6. And most importantly, the study was funded by Scientific Intake – the makers of the SMART device. While this does not guarantee a biased study, it surely points in that direction.

If you were reading carefully, you may have noticed that in the above quote, the authors refer to the “DDS system” and not the SMART device. From what I can gather, the DDS system was the original version of what is now the SMART device – only difference is that the SMART device now has an electronic component which allows you to track how many times you used it on a given day – pretty useless, but it allows for the excessively verbose name (Sensor Monitored Alimentary Restriction Therapy).

Also, you should note that despite the company being based originally out of the US, sales of the SMART device are only available in Canada. Their website states:

“SMART has been designated as a non-significant risk device by the U.S. FDA. It is considered investigational and not commercially available in the United States”


According to friend and director of the Wharton Medical Clinic, Dr. Sean Wharton, these devices go for about $500 each. In fact, Dr. Wharton has apparently been approached a few times by reps from Scientific Intake in an effort to get him and likely many other physicians across Canada in the obesity field to prescribe the fancy retainers to their patients.

I have my reservations about any proposed treatment for obesity, that does nothing but make eating a bit less comfortable. Nevertheless, I await the results of a long-term, randomized effectiveness trial of obese individuals prescribed the SMART device to make a final judgment.

Until then, I recommend you save your money.

As a side note, Dr. Yoni Freedhoff of Weighty Matters blog has previously discussed a very similar gimmick called the Diet Guard – basically a cheap version of Invisaligns, which do not straighten your teeth, but make eating uncomfortable.

Have a great weekend,


Walden, H., Martin, C., Ortego, L., Ryan, D., & Williamson, D. (2004). A New Dental Approach for Reducing Food Intake** Obesity, 12 (11), 1773-1780 DOI: 10.1038/oby.2004.220

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1 Response to "The SMART device for weight loss: jaw wiring for the 21st century?"

  1. docvini Said,

    You are absolutely right. I didn't know about this device but remember the jaw wiring as I've worked with people with eating disorders, obesity and other eating problems for 30 years. Your website provides a great service to everyone. I am a strong proponent of teaching people to be better consumers of all weight loss programs, products and aids. Thanks for helping out with that.

    Dr. Lavinia Rodriguez

    Posted on June 19, 2009 at 4:07 PM


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We are PhD students in the School of Kinesiology and Health Studies at Queen's University in Kingston, Ontario. Our research focuses on the relationships between obesity, physical activity, and health risk. This blog is our attempt to consider the many "cures" for obesity that we read about on a daily basis. Enjoy.


The opinions expressed here belong only to Peter and Travis and do not reflect the views of any organization. Any medical discussion on this page is intended to be of a general nature only. This page is not designed to give specific medical advice. If you have a medical problem you should consult your own physician for advice specific to your own situation.

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