People use smartphone apps to track investments, find a restaurant, book a flight or shop; they also use phone apps to help them lose weight and record their fitness progress.

But how well do these weight-loss apps really work?

There is a good deal that weight-loss apps can do to help dieters. They can provide information on the nutritional and caloric content of the food you eat. They make calorie counting easy. But they can't make you turn down that chocolate chip cookie. You are on your own there.

Can Apps Help You Lose Weight?

The results of a new study offer a picture of both what weight-loss apps can and cannot do to help us get healthier, and the ways in which they may be made more helpful to people trying to lose weight.

People who faithfully track calories tend to lose more weight than people who do not.

Few studies on the effectiveness of weight-loss apps have been done, so the researchers wanted to do a rigorous study of a promising app, MyFitnessPal, a free app available from the iTunes and the Android app stores, Brian Yoshio Laing, lead author of the study, told TheDoctor in an email.

He and his colleagues believe theirs is the first randomized trial of a weight-loss app. “The research on calorie tracking, however, is solid: people who faithfully track calories tend to lose more weight than people who do not,” said Laing, director of the Care Improvement Initiative for the Los Angeles County Department of Health.

Of the 212 people in the study, 107 were assigned to a group that received six months of usual care for weight loss — participants were told to choose any activities they’d like to try to lose weight.

Another 105 people were assigned to a group which received six months of the same usual care, plus help downloading and using MyFitnessPal.

One Group's Stellar Results
After six months, almost no members of either group had lost a significant amount of weight, and the amount of weight lost did not differ significantly between groups. The researchers also found that use of the app dropped off quickly after the first month, said Laing.

Ironically, the person who used the app the most and lost the most weight (almost 29 pounds) was not a study participant, but a member of the control group who found the app on their own. There is no substitute for determination when it comes to losing weight or becoming fit.

However, patients who used the app faithfully lost quite a bit of weight — 13 of 71 who used the app and completed a weigh-in six months later had lost almost 6 pounds (2.7 kg) or more.

Researchers and study participants did not know the name of the app, and it turned out that 14 of the 107 people in the control group had also used the app. Ironically, the person who used the app the most and lost more pounds (almost 29) than anyone in the project was not a study participant, but a member of the control group who had found the app on their own. Bottom line: there is no substitute for determination when it comes to losing weight or becoming fit.

It's Nice to Have Help
Although app use decreased sharply after the first month, when study participants filled out a questionnaire at the end of the 6-month study, most reported they liked the app and would continue using it.

When asked what they liked about MyFitnessPal, 88 percent said it was getting feedback on their progress, while 48 percent mentioned that it was fun to use. Not all reviews were glowing, however. Among those who gave reasons they stopped using the app, 84 percent said it was tedious to use, and 24 percent said it was too difficult to use.

Laing said feedback from study participants who had lost more than 10 pounds included the following: “I realized I was consuming 5,000 to 6,000 calories per day, and afterward I never ate that much again!” and “It really makes you look at what you’re eating. It helped me select healthier foods and stay on track.”

The investigators said a lack of time may have been to blame for the negative result. "I think most patients simply were not ready to commit the time to track calories — it takes several minutes to input everything you eat for each meal," Laing said.

A More Effective Fitness App

So how might MyFitnessPal and other apps be made more effective in helping users reach their weight loss goal? Based on patient responses, the authors believe that making it easier to enter meals and track calories would be helpful. Apps might be developed to assess users’ readiness to monitor themselves before use and then help prepare new users for the time commitment involved.

Adding game and competitive features to the app, perhaps with financial incentives, may help too, the researchers said. The apps can also be powerful when combined with a counseling program.

Since apps are being updated and improved all the time, it seems likely that they will become both more accessible and easy-to-use. as well as more effective. The apps “can be a great tool for patients who are motivated to track calories,” Laing said.

The study was published online recently in a supplement to the Annals of Internal Medicine.