Engagement Drives Weight Loss Among Smartphone Application Users

If weight loss is the primary target of weight-focused digital therapeutics, a new study suggests user engagement is the primary mechanism of action.

The study, published in BMC Nutrition, showed that nearly 9 in 10 patients (87.3%) who used a smartphone application designed around the ketogenic diet were able to lose weight with the program. However, the data also showed that user engagement was strongly associated with significant weight loss.

The study focused on the KetoCycle app, which offers meal planning and recipes, exercise workouts, and health tracking built around the ketogenic diet, a high-fat, low-carbohydrate diet that was initially developed to help control epilepsy in children, but has recently become popular as a weight-loss technique.

The app’s developer, Kilo Health, wanted to know what impact the app was having in real-world usage, so it retrospectively analyzed a cohort of more than 10,000 users who had used the app for at least a month and had logged their weight in the app multiple times.

The analysis showed that 18.3% of users lost more than 10% of their initial body weight while using the app, 39.3% lost between 5% and 10% of their weight and 42.3% of patients lost less than 5% of their body weight.

The study showed that active users were more likely to lose at least 5% of body weight, which the authors said was a clinically significant benchmark.

Kasparas Aleknavičius, MD, head of medical affairs at Kilo Health, said he believes one of the challenges of using digital solutions to prompt weight loss is that it is not just the features that matter, but also the ways in which the features are served to users.

He said the app is able to offer meaningful interventions in part because it is able to personalize its interventions, based on factors such as user data, past in-app actions, and the patient’s experience level with the diet.

“These engagement-enhancing analytical efforts are largely based on behavioral science best practices — challenges, rewards, nudging, negative/positive reinforcement, peer support — as well as users' data for stratification and personalization of these approaches,” he told Managed Healthcare Executive^®.

Though the study linked user engagement with weight loss, one question Kilo Health and other digital therapeutic makers must answer is whether their application is actually driving the health improvement, or merely capturing the activity of users who already have the motivation and means to improve their health, with or without the intervention.

Aleknavičius said the question is an important one. One way to answer it, he said, is to look at an app’s success at reviving users who become inactive.

“It is a big challenge to decide between correlation and causation,” he said, “but we clearly see from our own data that we are able to resurrect users that drop-off, or that users who receive nudging, stay longer in an app and achieve better results.”

Though the study and the company’s data suggest the app is working, Aleknavičius said the next challenge is to better understand which particular features and prompts are most effective, and for which users.

Aleknavičius said the company is in the process of conducting a second study that will look more deeply at engagement and retention. Engagement and retention, he said, are the main purposes of the application.

“[G]enerally speaking it is an app's main function: to keep users motivated, to motivate those who are failing, to help users get back on a successful streak and to do that in a very particular manner that would be suitable for each user individually,” he said.