A personalized smartphone app called iSIPsmarter helped people cut sugary drink intake by 30 ounces per day and lose 3% of their body weight over 18 months, with improvements maintained long after the program ended. According to Gram Research analysis of this randomized controlled trial, the interactive app with behavioral tracking and personalized action plans outperformed a basic educational website, suggesting digital tools can create lasting healthy habits around sugary beverages.
A new study shows that a smartphone app called iSIPsmarter helps people cut back on sugary drinks and keep the weight off for over a year. Researchers tracked 211 adults from rural areas who used either the interactive app or a basic website for information. The group using the app reduced their sugary drink intake by about 30 ounces per day and lost 3% of their body weight, while the basic website group saw much smaller changes. According to Gram Research analysis, these improvements stuck around 18 months after the program ended, suggesting that digital tools can create lasting healthy habits.
Key Statistics
A 2026 randomized controlled trial of 211 adults found that participants using the iSIPsmarter app reduced sugary beverage intake by 30.1 ounces per day and lost 3% of their body weight at 18 months post-intervention, compared to minimal changes in the basic website group.
According to research reviewed by Gram, 85% of the original 249 study participants completed the 18-month follow-up, and the improvements in reduced sugary drinks and weight loss were maintained long after the digital intervention program ended.
A 2026 study published in the Journal of the Academy of Nutrition and Dietetics found that the iSIPsmarter digital intervention produced an effect size of 0.58 for weight change and 0.34 for beverage reduction, indicating small to moderate but meaningful improvements over a basic website control.
Research shows that approximately one-third of the weight loss in the iSIPsmarter group came indirectly through reduced sugary beverage intake, while two-thirds came from other behavioral changes, suggesting the app helped participants make multiple health improvements.
The Quick Take
- What they studied: Whether a personalized smartphone app could help people drink fewer sugary beverages and maintain weight loss over 18 months
- Who participated: 211 adults from rural Appalachia and surrounding areas; mostly white (89%), female (83%), with lower incomes, and overweight or obese. About 85% of the original 249 participants completed the full study.
- Key finding: People using the interactive app (iSIPsmarter) cut their sugary drink intake by 30 ounces per day and lost 3% of their body weight. The comparison group using a basic website only reduced drinks by 21 ounces and saw almost no weight change.
- What it means for you: If you struggle with sugary drinks, a personalized digital tool might help you quit and keep the weight off long-term. However, results are modest—3% weight loss is meaningful but not dramatic—and this study focused on rural populations, so results may differ for others.
The Research Details
This was a randomized controlled trial, which is considered one of the strongest types of research. Researchers randomly assigned 249 adults to one of two groups: one received iSIPsmarter (an interactive app with six educational modules, behavior tracking, and personalized action plans), while the other got a basic patient education website with static information. Both groups were tracked at four time points over 18 months: at the start, after 9 weeks, at 6 months, and at 18 months. The study ran from 2021 to 2024.
The app was designed based on two important theories: the Theory of Planned Behavior (which looks at how intentions, attitudes, and social pressure affect choices) and health literacy concepts (making sure people understand health information). The comparison group received a self-guided website without personalized feedback, which allowed researchers to see if the interactive, personalized approach made a real difference.
Participants reported their drink intake using a validated questionnaire, and they weighed themselves using special scales connected to the internet that automatically recorded their weight. This combination of self-reported and objective measurements strengthens the reliability of the findings.
This research design is important because it shows whether the app actually caused the changes, not just whether people who used it happened to lose weight. By comparing the interactive app to a basic website, researchers could isolate the effect of personalization and interactivity. The 18-month follow-up is particularly valuable because most diet studies only track people for a few weeks or months—this one shows whether changes stick around long-term, which is what really matters for health.
The study had strong retention (85% of participants completed it), which means the results are based on most of the original group rather than just the most motivated people. The use of objective weight measurements (internet-connected scales) rather than self-reported weight reduces bias. The study was published in a peer-reviewed journal focused on nutrition science. However, the sample was mostly white and female from rural areas, so results may not apply equally to other populations. The effect sizes were small to moderate, meaning the improvements were real but not huge.
What the Results Show
At 18 months after the program ended, the iSIPsmarter group had reduced their sugary drink intake by 30.1 ounces per day (about 2.25 cans of soda), compared to 20.9 ounces per day in the basic website group. This difference was statistically significant, meaning it’s unlikely to have happened by chance. The app group also lost 3% of their body weight on average, while the website group showed essentially no weight change.
Importantly, these improvements were maintained long after the intervention ended. Participants weren’t using the app intensively at the 18-month mark—they had completed the program months earlier—yet they kept their new habits. This suggests the app helped people develop lasting behavioral changes rather than just temporary compliance.
The researchers also found that about one-third of the weight loss came directly from drinking fewer sugary beverages (the indirect effect), while about two-thirds came from other changes participants made (the direct effect). This suggests the app helped people make multiple healthy changes beyond just cutting sugary drinks.
The effect sizes were small to moderate (0.34 for beverage reduction, 0.58 for weight loss), which means the improvements were real and meaningful but not dramatic. A 3% weight loss is considered clinically meaningful for health improvements, even though it’s not a large transformation.
The study found that the benefits were consistent across the 18-month period—people didn’t regain the weight or return to drinking sugary beverages after the program ended. This maintenance of results is notable because many diet interventions show initial success followed by weight regain. The app’s structured approach with behavioral tracking and personalized action planning appears to have helped people internalize new habits rather than just follow temporary rules.
Previous research has shown that reducing sugary drink intake is one of the most effective ways to lose weight and improve health, but many people struggle to maintain these changes long-term. This study adds to that evidence by showing that a digital, personalized approach can support lasting change. Most prior studies on digital health interventions for weight loss have been shorter (3-6 months), so this 18-month follow-up provides valuable new information about durability. The modest weight loss (3%) aligns with other behavioral interventions but is smaller than what people might achieve with medication or surgery.
The study included mostly white, female, rural participants with lower incomes, so results may not apply equally to urban populations, men, or people of other racial backgrounds. The study relied partly on self-reported drink intake, which can be less accurate than objective measures, though the researchers used a validated questionnaire to minimize this problem. The comparison group received only a basic website, not an alternative active intervention, so we don’t know how iSIPsmarter compares to other digital health tools. The weight loss, while meaningful, was modest—3% is good for health but won’t transform someone’s appearance. Finally, we don’t know which specific features of the app (the tracking, the personalized plans, the educational modules) were most important for success.
The Bottom Line
If you drink sugary beverages regularly and want to reduce them, a personalized digital app like iSIPsmarter may help you cut back and lose weight. The evidence is strong (randomized controlled trial) but the weight loss is modest (3%). This approach works best if you’re willing to engage with the app regularly and make behavioral changes. People with lower health literacy or limited digital access may need additional support. Confidence level: Moderate to High for reducing sugary drinks; Moderate for weight loss.
This research is most relevant to adults who drink sugary beverages regularly and want to reduce intake and weight. It’s particularly applicable to people in rural areas, though the approach may work for others too. People with diabetes, prediabetes, or obesity have the most to gain from reducing sugary drinks. This may be less relevant for people who already drink few sugary beverages or who have medical conditions requiring different dietary approaches.
Most of the weight loss and beverage reduction happened in the first 6 months, but the study showed that people maintained these changes for at least 18 months. You shouldn’t expect immediate results—meaningful change takes weeks to months. The app’s personalized approach and tracking features appear to help people stick with changes over time rather than just achieving quick initial results.
Frequently Asked Questions
Can a phone app really help me stop drinking sugary drinks and lose weight?
Research shows personalized digital apps can help. A 2026 study found people using an interactive app reduced sugary drinks by 30 ounces daily and lost 3% body weight over 18 months, compared to minimal changes with basic websites. Results are modest but meaningful and lasted long-term.
How much weight can I expect to lose by cutting out sugary beverages?
The study showed 3% average weight loss, which is clinically meaningful for health but modest in appearance. Results vary by individual. About one-third of weight loss came from reduced sugary drinks; other lifestyle changes contributed the remaining two-thirds.
How long does it take to see results from reducing sugary drinks?
Most weight loss and beverage reduction occurred within the first 6 months in this study. However, meaningful change takes weeks to months of consistent effort. The key finding was that improvements were maintained for 18 months, showing lasting results rather than temporary changes.
Will I regain the weight after stopping the app program?
This study found that people maintained their weight loss and reduced sugary drink intake for at least 18 months after the program ended, suggesting the app helped build lasting habits rather than temporary compliance. However, individual results vary.
Who should use this type of digital health app for sugary drinks?
Adults who regularly drink sugary beverages and want to reduce intake and weight are ideal candidates. The study included rural, lower-income populations. People with diabetes, prediabetes, or obesity benefit most. Those with limited digital access may need additional support.
Want to Apply This Research?
- Track daily sugary beverage intake in ounces or number of servings. Set a weekly reduction goal (e.g., reduce by 5 ounces per week) and log each drink consumed. Monitor weight weekly on the same day and time, looking at weekly averages rather than daily fluctuations.
- Use the app to create a personalized action plan for replacing sugary drinks with water, unsweetened tea, or other beverages. Set reminders to drink water at specific times. Log each sugary drink you avoid, celebrating small wins to build motivation and track progress visually.
- Review your beverage intake and weight trends monthly rather than daily to see the bigger picture. Adjust your action plan if you’re not making progress. Check in with the app’s personalized recommendations every 4-6 weeks to stay engaged and address new challenges that arise.
This research demonstrates that a digital app can help reduce sugary beverage intake and support modest weight loss, but individual results vary. This study was conducted primarily in rural populations and may not apply equally to all groups. Before making significant dietary changes, especially if you have diabetes, heart disease, or other medical conditions, consult with your healthcare provider or registered dietitian. Weight loss of 3% is meaningful for health but modest in appearance. This article summarizes research findings and should not replace professional medical advice.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.
