Researchers tested a new smartphone app designed to help people with obesity lose weight by providing personalized meal plans, exercise routines, and motivational support. Over 6 months, 246 people used either the real app or a fake app while following a healthy diet. Both groups lost weight, but people who used the real app consistently (at least 40% of the time) lost significantly more weight than those who barely used it. The study suggests that staying engaged with a weight loss app matters more than just having one.

The Quick Take

  • What they studied: Whether a smartphone app that gives personalized diet plans, exercise routines, and behavioral coaching helps people lose more weight compared to a basic tracking app.
  • Who participated: 246 adults aged 18-65 years with obesity (BMI between 30-45) from two obesity treatment centers in Italy. About 84% of participants completed the full 6-month study.
  • Key finding: People who regularly used the real weight loss app lost about 7 kg (15 pounds) on average, while those who barely used it lost only 3.2 kg (7 pounds). People who used the fake app lost about 4 kg (9 pounds). The key difference: consistent app use mattered more than which app you had.
  • What it means for you: If you’re considering a weight loss app, the app itself may help, but your commitment to using it regularly is what really counts. Apps work best when you actually use them daily. This doesn’t replace medical advice—talk to your doctor before starting any weight loss program.

The Research Details

This was a carefully designed experiment called a randomized controlled trial. Researchers randomly assigned 246 people to one of two groups: one group got access to a sophisticated weight loss app called DTxO (Digital Therapeutics for Obesity) that provided personalized meal plans, exercise recommendations, and behavioral coaching. The other group got a basic app that only let them track their food and exercise without any feedback or guidance.

Both groups followed the same Mediterranean-style diet with a 800-calorie daily reduction (eating about 800 fewer calories than their body needs). The study lasted 6 months, and researchers carefully tracked how much weight people lost and how often they used their assigned app.

The clever part: participants didn’t know if they had the real app or the fake one (called a ‘single-blind’ design), which helps prevent people from losing weight just because they think they should. Researchers used statistical models to figure out which factors were most important for weight loss success.

This research approach is important because it answers a real-world question: does a fancy app actually work better than a simple one? By randomly assigning people to groups, researchers can be more confident that any differences in weight loss are due to the app itself, not because different types of people chose different apps. The 6-month timeframe is long enough to see if benefits stick around, and tracking app usage tells us whether people actually use what they’re given.

This study has several strengths: it was conducted at real obesity treatment centers, used proper randomization, had a good completion rate (84% of people finished), and measured multiple health markers beyond just weight. However, it was only done in Italy with relatively small numbers of highly engaged participants, so results might differ in other countries or with less motivated people. The study was published in a reputable journal focused on digital health research.

What the Results Show

After 6 months, both groups lost weight, which was good news. The DTxO app group lost an average of 3.2 kg (about 7 pounds), while the placebo app group lost 4.0 kg (about 9 pounds). Surprisingly, this difference wasn’t statistically significant—meaning it could have happened by chance. Both groups also lost about 3-4% of their body weight.

However, when researchers looked at people who actually used their apps regularly (at least 40% of the expected time), the picture changed dramatically. People who consistently used the real DTxO app lost 7.02 kg (about 15.5 pounds) on average, compared to only 3.50 kg (7.7 pounds) for those who consistently used the placebo app. This difference was real and meaningful.

The pattern was clear: using the app more often was linked to losing more weight. For every increase in app usage, weight loss improved. People who used the DTxO app for about 42 minutes per day on average did better than those who used it less frequently.

Beyond weight loss, researchers also measured waist circumference, blood pressure, blood sugar levels, and cholesterol. The study found that consistent app use was associated with improvements in these health markers as well, though the paper doesn’t provide detailed numbers for all of these. The finding that adherence (actually using the app) was the strongest predictor of success suggests that motivation and engagement matter more than the app’s features alone.

Previous research has shown that digital tools can help with weight loss, but results have been mixed. This study adds important evidence that the app itself might be less important than how much you actually use it. Other studies on weight loss programs have found similar patterns—people who stick with any program tend to do better than those who don’t. This research confirms that pattern applies to digital apps too.

The study was relatively small and only included people in Italy, so results might not apply everywhere. Participants were also quite motivated (they volunteered for a weight loss study), so the app might not work as well for people who are less interested in losing weight. The study only lasted 6 months, so we don’t know if weight loss continues or comes back after that. Additionally, everyone followed a specific diet plan, so we don’t know how well the app works without professional dietary guidance. Finally, the placebo app still allowed tracking, which might have helped people in that group more than a true control would.

The Bottom Line

If you’re considering a weight loss app: (1) Choose one that provides personalized guidance, not just tracking—moderate confidence based on this study. (2) Commit to using it regularly; the app only works if you actually use it—high confidence. (3) Combine the app with a structured eating plan (like Mediterranean diet)—moderate confidence. (4) Expect gradual weight loss (about 1-2 pounds per week for consistent users)—moderate confidence. Always consult your doctor before starting a weight loss program, especially if you have health conditions.

This research is most relevant for adults with obesity who want to lose weight and are comfortable using smartphone apps. It’s particularly useful for people who can’t attend regular in-person weight loss counseling due to time or cost. However, if you have serious health conditions, take multiple medications, or have a history of eating disorders, you should work with a healthcare provider rather than relying on an app alone. The study doesn’t tell us if this approach works for teenagers or older adults.

Based on this study, people who consistently used the app lost about 7 kg over 6 months, which is roughly 1.2 kg (2.6 pounds) per month. You might see initial changes within 2-4 weeks if you’re consistent, but meaningful weight loss typically takes 8-12 weeks to become obvious. Remember that weight loss isn’t always steady—some weeks you’ll lose more, some weeks less.

Want to Apply This Research?

  • Track daily app usage minutes and weekly weight loss together. Set a goal of using the app at least 30 minutes daily (the study showed 40+ minutes was most effective). Log your weight weekly on the same day and time to see the connection between consistent app use and weight changes.
  • Start with one specific behavior change: commit to opening the app at the same time each day (like after breakfast or before dinner). Use the app’s meal planning feature to plan tomorrow’s meals today, and use the exercise routine feature at least 3 times per week. Track these actions in the app to build the habit.
  • Create a simple weekly check-in: every Sunday, note how many days you used the app that week and your current weight. After 4 weeks, review the pattern—you should see that weeks with more app usage correlate with better weight loss. Adjust your app usage goal if needed to maintain at least 40% of expected daily use (about 30-40 minutes per day based on this study).

This research describes one study on a specific weight loss app and should not be considered medical advice. Weight loss is complex and influenced by many factors including genetics, medications, underlying health conditions, and individual circumstances. Before starting any weight loss program or using a weight loss app, consult with your healthcare provider, especially if you have diabetes, heart disease, take medications that affect weight, or have a history of eating disorders. This study does not replace professional medical supervision. Results may vary significantly between individuals, and what works for study participants may not work the same way for you. If you experience any adverse effects or health concerns while using a weight loss app, stop and contact your healthcare provider immediately.