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NewsBLOG | Can Wearable Technology Help in the Obesity Clinic?

Can Wearable Technology Help in the Obesity Clinic?


Author: Dr Tim Lobstein
Director of Policy, World Obesity Federation


A trial reported recently in JAMA (1) examined whether adding wearable technology to a behavioural intervention would improve weight loss among young adults attending an outpatient obesity clinic. The results were unexpected.

Wearable technology consists of sensor able to detect movement and sedentary behaviour and can also monitor cardiovascular activity and physical signs of stress.  Apps on smartphones can link to the sensors and analyse the output, providing indicators for overall physical activity and energy output. Additional smartphone apps can help patients keep records of their daily dietary intake. Taken together the technology provides great ‘patient empowerment’, helping patients reflect on their health behaviour, monitor their change in behaviour and generally feel in greater control of their treatment.

But does it actually help in practice? The JAMA paper suggests not. The patients in the group with wearable technology lost weight, but not as much as those without the wearable technology.

There could be many reasons. The unreliability of the sensors and their outputs is an issue: when several different brands of sensor are worn simultaneously they can come up with different estimates of the activity levels of the wearer (2). In a sense, this may not be important if the wearer only wants to know whether he or she has made a significant increase on their daily level of activity – as long as the sensor’s inaccuracy is consistent, any increase or decrease should show up.

Accuracy of dietary intake is harder to ensure. Most dietary intake apps use either European or American databases of food items and ask the user to name or identify the foods they have eaten, and the amounts of each food. With complex foods, such as a pizza or mixed salad, either the quantity or the component ingredients may not be obvious to the user. And with a database of several thousand food items, finding the right description can be tedious and put off the user from recording their intake accurately.

However, from a clinical perspective, it may not be strictly necessary to have accurate records of every item consumed. Health professionals helping their clients manage their weight might be content to see a general change in the dietary patterns, such as a reduced number of between-meal snacks, fewer sugar-sweetened beverages, a greater variety of fruits and vegetables, and a healthy breakfast. These four indicators alone could be more useful than a set of daily diaries that do not reflect actual calorie intake.

The World Obesity Federation is participating in a research project on the use of wearable devices for helping weight loss in a clinical setting – the EU-supported DAPHNE project (3). In one arm of this study adolescents attending a weight management clinic in an Italian hospital were asked to wear movement sensors and complete food diaries, and the results were made available to the young person, as in the JAMA trial, but the results were also transmitted through a Cloud-based system to the health professionals in the clinic. Over a two-month period the adolescents were monitored and asked about their experiences. By the end of the second month they were wearing the sensors on fewer than two days per week, and using the dietary diaries on average once per week.

Despite this apparent lack of motivation, the young people described the experience as empowering, giving them control over their own clinical treatment using digital systems they were familiar with. Furthermore, several of the children in the trial showed a significant decrease in body mass over the period.

Quite possibly this is an example of the Hawthorne Effect, i.e. the individual’s behaviour changes because of the fact that he or she is being observed in an experiment. In this case, the clinical team can observe the outputs from the patient’s devices, and the patient knows it.

But perhaps that is the real treatment effect we seek. Even if it is a form of placebo, the transmission of the data from patient to doctor could itself be motivational. The doctor or clinical team colleague will have a record of a patient’s behaviour between appointments, for which the patient is accountable. It could increase the motivation to comply with the doctor’s treatment instructions, as if the doctor is able to see your progress every day. Without such continuing supervision the patient may be less motivated and the sophisticated technology largely ineffective. And if this is the case, then it may not be important whether the doctor actually looks at the patient data between appointments, as long as the patient knows it could occur.

The DAPHNE trial was only a pilot study to show feasibility, and the results are only speculative. Nevertheless, perhaps wearable technology has a role, not so much for ‘patient empowerment’ but for ‘patient participation’. Patients using the sensors on their own may not be motivated so much as patients feeling that they are working with their clinicians.

An earlier version of this blog appeared on the British Medical Journal’s blog page.


The DAPHNE project is co-funded under the European Commission FP7 research programme (grant 610440). The European Commission is not responsible for any use that may be made of the material arising.