Weight Loss Apps: Can They Motivate the Unwilling?

Here's a review of science tracking the success of diet apps.

Posted Dec 03, 2019

As holiday shopping accelerates, the devices and apps that track food intake, exercise frequency and duration, as well as sleep cycles and stress, will be advertised as important aids to living a healthier lifestyle. Those who already have such aids may be putting them away until January 2, when the country seems to go on a New Year’s resolution diet. And others may be trying on their new watches and wrist bands, scanning their newly downloaded apps for information on how to be maximally successful in their weight-loss endeavor.

Do they work? Does recording every morsel of food consumed into a program that identifies its caloric content, along with major and minor nutrients, support and sustain the effort to lose weight? Can devices and apps that are programmed to remind the user to move, to sleep longer, decrease stress, and avoid emotional overeating, along with providing information on whether the user met daily goals of reduced calorie intake, work? And if so, do they work as well or better than face-to-face groups or individual counseling sessions?

One study compared the use of an online weight-loss program that included lessons in behavioral change, self-monitoring of weight, exercise, and the recording of food intake with a traditional weight-loss program. This program involved frequent group sessions in which dieters received instructions on changing their eating behavior and personal interactions with the support staff, in regard to what they were eating and their level of physical activity. A control group was told only to keep track of their food intake with food logs and received written responses to their submitted food and weight records.   

The weight-loss results were somewhat surprising. Two hundred and seventy-six subjects were divided into three groups, and each group lost about the same amount of weight. The only difference—and it should not be minimized—is that the number of dropouts was much greater in the control group, perhaps due to the absence of interactive feedback on their progress. The efficacy of a remote, computer-driven, weight-loss support program seems to be supported by this study, according to the authors, and adherence to the program equaled that of participants enrolled in actual as opposed to virtual meetings.

However, in another study, the subjects failed to respond to a weight-loss app’s requests to track food intake and weight by evaluating whether people can change more than one behavior at a time. 

The researchers asked one group of dieters only to note their weight for a month on an app, and although they received a suggestion about exercise and other ways of living a healthier lifestyle, they did not get a diet plan. Another group interacted with an app that told them to monitor their weight daily, follow a diet, and follow behavioral change suggestions. A third group received only diet advice from an app.

The group asked to track weight, food intake, and respond to behavioral suggestions simultaneously did best in adherence to logging in and interacting with the program. The two other groups interacted with the app’s program only sporadically or not at all. The authors speculate that participants who were failing to lose weight lost interest in using the apps and ignored requests for information on weight and food intake. Obviously, the apps were unable to motivate the now-disinterested dieter in interacting with their programs.

People typically drop out of weight-loss programs when they find their weight loss is too slow or has stopped. When my weight-loss clients failed to attend a group or individual weight loss meeting and were contacted, they said they dropped out because “My diet failed me.” However, an app programmed to help the dieter achieve weight-loss goals doesn’t require explanations or excuses to explain the failure to lose weight or eat more healthily.

There is no judgment or criticism from the computer program if food tracking isn’t done, or exercise not performed, as there might be from a weight-loss facilitator or physician. No app, unlike a family member or friend, is going to tell the dieter that they will probably fail at this attempt to lose weight because they have a history of diet failures. And unlike weekly meetings of support groups and/or individual counseling, the app is always available, 24/7. Thus, using an app to monitor and support weight-loss efforts might be more effective in helping the dieter lose weight than human interactions, especially when the weight loss slows.

Many years ago, a then extremely popular weight-loss program insisted that the dieter fill out a food log daily and present the food log at that evening’s meeting with a staff member. Weight was measured every evening as well, and dieters were advised on how to improve food choices. Dieters were initially successful because of the very frequent monitoring of food intake and weight.

But as one participant told me, filling out the food logs became tedious and unpleasant: “We all would sit in the parking lot of the clinic and fill out our food logs before our appointments. Of course, we just made up what we ate. Who was going to put down potato chips or ice cream?”

Food-tracking apps are easier to use than a paper and pencil record of food intake, but they also require discipline and motivation and a high tolerance for repetitive activity. Apps that also track exercise are very easy to use as well but are irrelevant if the individual wearing the activity tracking device is immobile. Suggestions on changing behavior to reduce emotional overeating or decrease portion size are sensible and may work if followed.

People benefit from these apps because they are able to improve the nutritional quality of what is eaten or motivate exercise because the app gives instant praise when physical activity occurs. But are apps able to motivate the disinterested or discouraged dieter? Are there apps that entice users who stop tracking food consumption or refuse to exercise to begin again? Are there apps that really understand why we eat too much? Maybe the next generation of such devices will accomplish this. Or maybe not.  


“Comparison of Smartphone‐Based Behavioral Obesity Treatment With Gold Standard Group Treatment and Control: A Randomized Trial,” Thomas, J, Bond D, Raynor H et al, Obesity 2019; 27:572-580.

“Comparing Self-Monitoring Strategies for Weight Loss in a Smartphone App: Randomized Controlled Trial,” Patel M, Hopkins C, Brooks T, Bennett G,    JMIR Mhealth Uhealth 2019; 12209e