A Smartphone App–Based Lifestyle Intervention Promotes Weight Loss—Results of a Prospective, Randomized, Controlled Clinical Trial (RCT)

Abstract

Despite widespread use of smartphones and wearables, we have limited evidence that they aid weight loss or lifestyle. Here, we report results of a 6-month RCT of our smartphone app-based lifestyle intervention vs. standard of care (in-person weight management visits at 0, 3, and 6 months) in a cohort of overweight or obese subjects. The app downloads objective data of daily weights from smartscales and physical activity from 3-axis accelerometers. The technology allows peer social networking and remote professional coaching employing behavior modification techniques delivered via group and private messaging, emoticons, shared activity and weight data, shared photographs of meals, and a virtual reward system for behavior modification. Intervention group: n=13, 85% F, age 39.5 ± 3.71 y, initial weight 94.3 ± 3.42 kg, BMI 34.5 ± 1.3 kg/m2. Control group: n=15, 86% F, age 45.1 ± 3.31 y, initial weight 92.3 ± 4.37 kg, BMI 33.8 ± 1.kg/m2 (means ± SE). We found a clinically and statistically significant weight difference of -4.2 ± 2.0 kg (95% CI -8.3 to -0.02 p=0.0488) after 6 months of our smartphone app-based lifestyle intervention (prespecified primary outcome, intervention vs. control). In the intervention group, weight change was -7.2 ± 1.8 kg (95% CI -11.1 to -3.3, p = 0.0017); % weight change was -7.9% ± 2.2% (95% CI -12.6 to -3.2, p=0.0031). Weight change significantly associated with median step counts (Pearson’s correlation coefficient r=-0.61, p=0.027), numbers of text messages from each subject (r=-0.83, p=0.0005), and numbers of diet photos shared (r =-0.83 p=0.0005). Our app-based lifestyle intervention met the prespecified primary outcome of clinically meaningful and statistically significant weight loss at 6 months over control. The strongest correlations with weight loss in the intervention group were physical activity (step counts) and subjects’ engagement in behavior modification coaching (messages and diet photos). Disclosure C. Vaz: None. A.G. Suthar: None. B.T. Pousti: None. S.M. Aye: None. K. Williams: Stock/Shareholder; Self; Hygieia, Gemphire, Inc.. Advisory Panel; Self; Gemphire, Inc.. H. Zhao: None.

The Effectiveness of Combining Nonmobile Interventions With the Use of Smartphone Apps With Various Features for Weight Loss: Systematic Review and Meta-analysis

“…Consequently, the meta-analysis and subgroup analysis were performed for the 3- and 6-month outcomes. Compared with the control group, smartphone apps resulted in a pooled net estimate weight loss of –1.99 kg (95% CI –2.19 to –1.79 kg; I 2 =81%) and –2.80 kg (95% CI –3.03 to –2.56 kg; I 2 =90%) at 3 and 6 months, respectively ( Figure 3 [ 27 , 28 , 32 , 33 , 36 , 39 - 42 , 44 , 48 , 52 , 58 , 60 ] and Figure 4 [ 12 , 27 - 29 , 35 - 37 , 39 , 43 , 46 - 48 , 51 , 52 , 54 , 57 , 58 ]). Subgroup analysis was performed based on the different interventions that accompanied the use of the mobile app.…”

“…Another subgroup analysis was performed based on the type of behavioral interventions, human-based versus passive. When compared with control, only the combination of the mobile app with intensive behavior coaching or feedback by a human coach showed a statistically significant weight loss of –2.03 kg (95% CI –2.80 to –1.26 kg; I 2 =83%) and –2.63 kg (95% CI –2.97 to –2.29 kg; I 2 =91%) at 3 and 6 months, respectively ( Figure 5 [ 27 , 28 , 32 , 33 , 36 , 42 , 44 , 48 , 50 , 52 , 55 ] and Figure 6 [ 27 - 29 , 35 , 36 , 43 , 46 , 47 , 51 , 52 , 54 , 57 ]). The funnel plots ( Multimedia Appendix 3 ) were symmetrical, suggesting that there was no publication bias.…”

“… Forest plot of the effectiveness of mobile phone apps and the additional interventions on weight loss at 6 months [ 12 , 27 - 29 , 35 - 37 , 39 , 43 , 46 - 48 , 51 , 52 , 54 , 57 , 58 ]. IV: inverse variance method.…”

The App Behavior Change Scale: Creation of a Scale to Assess the Potential of Apps to Promote Behavior Change

“…This scale will allow researchers to investigate the behavior change potential of a large number of apps reasonably quickly. This is important, as the fast-moving pace of app technology means that although randomized controlled trials (RCTs) remain important in understanding the impacts of individual apps on behavior [86], it has been suggested that the RCT may not be the most appropriate method to generate evidence around mobile apps [28]. RCTs can take a significant amount of time in planning and design meaning that by the time the RCT is available for publication, the information is no longer current [28].…”

Lifestyle Changes

“…These approaches have been shown to lead to better maintained weight loss and physical activity measurements as well as increased mental health outcomes. In addition to traditional methods of intervention delivery, recent trials have shown promise for the use of electronic wearable activity monitors and other mHealth behavior change interventions in decreasing sedentary behavior, increasing physical activity, and improving diet (Cadmus-Bertram et al 2015;Guitar et al 2018;Vaz et al 2018).…”