Long-term Effectiveness of a Smartphone App Combined With a Smart Band on Weight Loss, Physical Activity, and Caloric Intake in a Population With Overweight and Obesity (Evident 3 Study): Randomized Controlled Trial

Journal of Medical Internet Research

May 2021

DOI: 10.2196/30416

Citations:66

Influential Citations:2

Interventional (Human) Studies

Enhanced Details

Methods

Design: Multicenter, randomized, parallel-group controlled trial (Evident 3). Setting: 5 primary care centers in Spain. Participants: 650 adults aged 20-65 with overweight/obesity (BMI 27.5-40 kg/m2) and sedentary lifestyle; IG 318 and CG 332. Intervention: IG received a 3-month low-intensity multicomponent mHealth program using a smartphone app (Evident 3) and a wearable band plus brief counseling; CG received brief counseling only. Assessments at baseline, 3 months, and 12 months; analyses by intention-to-treat. Blinding: participants could not be blinded to assignment.

Results

At 12 months, IG showed modest improvements versus CG in weight and several body composition indices: weight −0.26 kg (95% CI −1.21 to 0.70; P=.02), BMI −0.06 (95% CI −0.41 to 0.28; P=.01), waist-height ratio −0.25 (95% CI −0.94 to 0.44; P=.03), body adiposity index −0.33 (95% CI −0.77 to 0.11; P=.03), waist circumference −0.48 cm (95% CI −1.62 to 0.66; P=.04), hip circumference −0.69 cm (95% CI −1.62 to 0.25; P=.03). Both groups lowered daily caloric intake and increased adherence to the Mediterranean diet, with no between-group differences. IG increased light physical activity time by 32.6 minutes/week (95% CI −30.31 to 95.04; P=.02) vs CG. Subgroup analyses showed changes in body composition variables in women, people aged >50 years, and married people. Conclusions: The low-intensity Evident 3 intervention yielded short-term benefits in weight, some body composition metrics, and light physical activity at 3 months, but the downward trend was not maintained after device removal at 12 months; nutritional outcomes did not differ between groups.

Limitations

Dropout rate was 31.8% (207/650), potentially biasing results; dropouts were younger and heavier; data from the smart band did not allow daily use/adherence assessment; participants could not be blinded to group assignment; the 3-month exposure may be insufficient to identify lasting changes; subgroup analyses may be underpowered and group sizes were unequal; generalizability limited to Spanish primary care adults with overweight/obesity.

Abstract

Background Multicomponent mobile health approaches can improve lifestyle intervention results, although little is known about their long-term effectiveness. Objective This study aims to evaluate the long-term effectiveness (12 months) of a multicomponent mobile health intervention—combining a smartphone app, an activity tracker wristband, and brief counseling, compared with a brief counseling group only—on weight loss and improving body composition, physical activity, and caloric intake in Spanish sedentary adults with overweight or obesity. Methods We conducted a randomized controlled, multicenter clinical trial (Evident 3). A total of 650 participants were recruited from 5 primary care centers, with 318 participants in the intervention group (IG) and 332 in the control group (CG). All participants were briefly counseled about a healthy diet and physical activity at the baseline visit. For the 3-month intervention period, the IG received training to use the app to promote healthy lifestyles and the smart band (Mi Band 2, Xiaomi). All measurements were performed at baseline and at 3 and 12 months. Physical activity was measured using the International Physical Activity Questionnaire–Short Form. Nutritional habits were assessed using the Food Frequency Questionnaire and Adherence to Mediterranean diet questionnaire. Results Of the 650 participants included, 563 (86.6%) completed the 3-month visit and 443 (68.2%) completed the 12-month visit. After 12 months, the IG showed net differences in weight (−0.26, 95% CI −1.21 to 0.70 kg; P=.02), BMI (−0.06, 95% CI −0.41 to 0.28 points; P=.01), waist-height ratio (−0.25, 95% CI −0.94 to 0.44; P=.03), body adiposity index (−0.33, 95% CI −0.77 to 0.11; P=.03), waist circumference (−0.48, 95% CI −1.62 to 0.66 cm, P=.04) and hip circumference (−0.69, 95% CI –1.62 to 0.25 cm; P=.03). Both groups lowered daily caloric intake and increased adherence to the Mediterranean diet, with no differences between the groups. The IG increased light physical activity time (32.6, 95% CI −30.3 to 95.04 min/week; P=.02) compared with the CG. Analyses by subgroup showed changes in body composition variables in women, people aged >50 years, and married people. Conclusions The low-intensity intervention of the Evident 3 study showed, in the IG, benefits in weight loss, some body composition variables, and time spent in light physical activity compared with the CG at 3 months, but once the devices were collected, the downward trend was not maintained at the 12-month follow-up. No differences in nutritional outcomes were observed between the groups. Trial Registration ClinicalTrials.gov NCT03175614; https://clinicaltrials.gov/ct2/show/NCT03175614 International Registered Report Identifier (IRRID) RR2-10.1097/MD.0000000000009633 show less