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Conventional face-to-face weight loss and weight control programs are very labor intensive for both the patient and the provider. It is unclear to what extent conventional programs can be (partially) completed by mobile health (mHealth) apps.
The aim of this study was to compare the effectiveness of different weight loss programs using a combination of conventional and mobile programs among adults who are overweight (body mass index [BMI]>29 kg/m²).
A single-blinded randomized controlled trial among obese adults was performed from September 2015 to March 2016. The study took place in Leuven, Belgium. Of the 102 eligible (BMI >29 kg/m²) adults, 81 (79%) completed the study. The three intervention groups consisted of a conventional face-to-face weight loss program, a weight loss app program (app group), and a partial face-to-face and partial app program (combi group). All intervention groups received the same advice from a dietician and a physical activity coach during a 12-week period. The control group did not receive any information during the same period. Primary outcomes were weight reduction (5% decrease of baseline weight in kg), BMI, metabolic risk factors, dietary pattern, and physical activity.
Significant more participants in all three intervention groups lost at least 5% or more of their weight at baseline compared with the control group. No significant difference was found between the combi group and the conventional group. A trend was found that more participants in the combi group lost 5% or more compared with the app group (19%),
The results of this study show that a conventional weight loss program could partially be completed with an mHealth program without affecting the effectiveness.
Clinicaltrials.gov NCT02595671; https://clinicaltrials.gov/ct2/show/NCT02595671 (Archived by WebCite at http://www.webcitation.org/6w1H0x1Q6)
Obesity remains a serious global health challenge. Approximately 37% (2.1 billion) of the adult world population is overweight or obese, with a prevalence of over 60% in Australia and the United States and between 15% and 30% in Europe [
Conventional face-to-face weight loss and weight control programs, including components for healthy eating and physical activity, have been found to be effective [
New generations of mobile health (mHealth) technologies that make use of mobile phones or tablets for delivering health information and real-time tailored feedback are emerging and offer good potential for delivery of weight loss programs that are less labor intensive [
So far, most studies evaluated the effectiveness of a conventional face-to-face weight loss program, an mHealth weight loss program, or a conventional program plus mHealth. It remains unclear to what extent a conventional face-to-face weight loss program could (partially) be completed with a weight loss app. Therefore, the aim of this study was to compare the effectiveness of three weight loss programs (eg, conventional face-to-face weight loss program, a mobile weight loss app [app group], and a partial face-to-face or partial app program [combi group]) with no intervention program among adults with obesity (BMI>29 kg/m²).
From September 2015 to November 2015, overweight adults living in the Leuven (Belgium) region were recruited for this single-blinded randomized controlled trial (RCT). Inclusion criteria included a body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) between 29 and 34 kg/m² (based on patient metabolic characteristics visiting registered dieticians and qualified physical activity coach in a primary care setting), in the age range of 18 to 65 years, having an email address, and having a personal computer or tablet, or mobile phone. The exclusion criteria were suffering from a known physical (eg, orthopedic limitations and stroke) and/or psychological (eg, eating disorders and depression) disease or comorbidity, intake of any medication with possible impact on body weight, endurance capacity, currently treated for diabetes (both type 1 and 2), sleep apnea determined during the last year, a history of systematic strength or endurance training (moderate to high intensity training more than once a week) in the year before the beginning of the trial, a history of following a supervised dietary advice in the year before the beginning of the trial, having a history of bariatric surgery or any other malabsorption-related disease, and pregnancy.
Through flyers, social media, and advertisements in local media, overweight and obese adults were invited to participate in a 12-week weight loss intervention. Every person with an interest in the study was invited to attend a general information session about health risks related to overweight, importance of regular physical activity, healthy eating for successful weight loss, and information about this study. After this session, the invitees could sign up for participation in the study. After signing informed consent, the principle investigator allocated the participants in the different groups by means of random number allocation in Excel (Microsoft; see
Description of intervention.
Participants of this group received an individualized diet plan from a registered dietician. Furthermore, each participant received a personalized physical activity plan for 12 weeks from a physical activity coach. In both plans, behavioral change techniques such as self-monitoring, action planning, and relapse prevention were incorporated [
Participants in this group received an account to use the digital mobile app. The app consisted of six parts: digital advice for their dietary pattern and physical activity, how to challenge themselves, self-monitoring (step count), library with (scientific) information on nutrition and physical activity but also recipes, a help button for advice, and a link to a Facebook group. The app was available for Android and iPhone operating system (iOS, Apple Inc). The content of the digital advice matched with the conventional advice. See
The subjects of this group received first a 1-hour intake with the dietician and a 1-hour intake with the physical activity coach in the first week. Within these consultations, they received the same information as the conventional treatment group. Additionally, these subjects received an account to use the mobile weight loss app. In the seventh week, participants received an additional face-to-face session with the physical activity coach. Compared with the conventional group, participants received two lesser 30 min counseling sessions with a dietitian and physical activity coach during the intervention.
Participants were informed that they were on the waiting list for the weight loss program.
Screenshots of the mobile weight loss app.
Percentage of participants with at least 5% decrease in baseline weight in kg (5% criterion) [
Waist circumference (WC) was measured with an inelastic tape, placed directly on the skin, perpendicularly to the long axis of the body while the subject stood balanced on both feet, with both arms hanging freely [
High density lipoprotein cholesterol (HDL-C) and triglycerides (TG) were determined using a CardioChek Point-of-Care Self-Test device (Cardiochek PA, Polymer Technology Systems Inc., Indianapolis, IN, United States) [
A validated digital Food Frequency Questionnaire (FFQ), developed to estimate the overall dietary pattern, was used to measure dietary changes during the 12-week period [
Physical activity was measured objectively and by means of a self-administrated questionnaire. Objective measurement of physical activity was provided with a tri-axial accelerometer (ActiGraph, model wGT3X-BT, LLC, Pensacola, Florida, United States) [
The International Physical Activity Questionnaire-Short Form (IPAQ-SF) was used to estimate the amount of self-reported physical activity in the past week [
All results were expressed as mean (standard deviation, SD) and mean difference (SD). Intention-to-treat (ITT) analyses were performed. Differences between groups in the baseline data regarding anthropometric (including BMI), dietary patterns, physical activity, and cardio-metabolic risk factors were analyzed using an analysis of variance (ANOVA) comparison test or chi-square test. BMI, dietary pattern, physical activity, and cardio-metabolic risk factors data were analyzed using a 4 × 2 mixed-model repeated-measures ANOVA with group and time (pre vs post) as factors and gender as covariate. Significant interactions were further analyzed by means of Tukey test
The sample size for equivalence studies was calculated based on the 5% criterion for weight loss. On the basis of the results of a recent RCT [
Of the 122 initially recruited participants, 102 completed the trial (79%; 102/122; see
Significant more participants in all three intervention groups lost at least 5% or more of their weight at baseline compared with the control group (see
A significant time x group effect was found for BMI (
No significant differences were found between the conventional group and the app group and between the conventional group and the combi group (
A significant time x group effect was found for cardio-metabolic risk factors (
No significant differences were found between the three intervention groups. However, all intervention groups had significant higher decreases in cardio-metabolic risk factors compared with the control group (all
No significant group x time effect was found for dietary pattern (see
No significant group x time effects were found for MVPA. Furthermore, no significant changes were found in any of the groups with regard to the percentage of participants that fulfilled the IPAQ minimally active criteria and the HEPA active criteria (see
Flowchart of trial.
Baseline characteristics of the participating adults.
Characteristics | Control group (n=18) | Conventional group (n=21) | App group (n=24) | Combi group (n=18) |
Age (years), mean (SDa) | 45 (10.2) | 46 (9.2) | 44 (12.4) | 45 (9.6) |
Female (%) | 75 | 84 | 72 | 48b |
Weight (kg), mean (SD) | 92 (10.2) | 90 (9.1) | 90 (10.1) | 96 (12.0) |
aSD: standard deviation.
b
Weight loss (percentage of persons losing 5% of baseline weight).
Changes in body mass index (BMI), metabolic risk factors, physical activity, and dietary pattern.
Factors | Control group (n=22) | Conventional group (n=28) | App group (n=30) | Combi group (n=22) | |||||
Pre, mean |
Post, mean |
Pre, mean |
Post, mean |
Pre, mean |
Post, mean |
Pre, mean |
Post, mean |
||
BMIb | 32 (2.0) | 0.1 (1.0) | 32 (2.0) | −1.0 (1.3) | 32 (2.1) | −0.7 (1.0) | 32 (2.2) | −1.3 (1.2) | |
Metabolic risk | 2.9 (1.2) | 0.5 (1.4) | 3.0 (1.0) | −0.6 (1.4) | 3.2 (1.3) | −0.5 (1.5) | 2.9 (1.0) | −0.3 (1.1) | |
Category 2 | 17 (59%) | 0 (0.7) | 16 (64%) | 0.11 (0.6) | 14 (58%) | 0.05 (0.6) | 20 (71%) | 0.04 (0.6) | |
HEPAc | 6 (21%) | −0.06 (0.4) | 7 (28%) | 0.0 (0.6) | 3 (11%) | −0.04 (0.5) | 7 (25%) | −0.08 (0.5) | |
MVPAd (min) | 324 (89) | −1.7 (63.7) | 314 (82) | 11.8 (61.4) | 333 (82) | 3.6 (72.8) | 348 (90) | −33.5 (39.8) | |
Overall score nutrition pattern | 69.5 (13.1) | 3.0 (6.8) | 69.7 (11.5) | 11.,2 (13.7) | 71.5 (12.6) | 8.1 (13.8) | 70.0 (14.9) | 8.7 (12.6) | |
Energy intake (kcal) | 1534.2 (548.3) | −115.1 (381.8) | 1453.3 (413.6) | −392.7 (302.9) | 1489.5 (414.9) | −192.2 (247.4) | 1456.5 (397.6) | −287.3 (277.3) |
aSD: standard deviation.
bBMI: body mass index.
cHEPA: health enhancing physical activity.
dMVPA: moderate to vigorous physical activity.
This study evaluated whether conventional weight loss programs could be (partially) completed with an mHealth app. The results of our study show that when replacing a part of the conventional program by an mHealth app does not affect the effectiveness of the program. Although an mHealth app as a single intervention also showed positive results on BMI and weight reduction, this change was smaller compared with the conventional and combi group.
Our results with regard to BMI and weight reduction are in line with previous studies [
In our study, metabolic risk factors decreased in our intervention groups. These results are in line with other studies, showing that a combination of a calorie intake reduction combined with physical activity reduces metabolic risk factors [
All groups in our study reduced their energy intake during the trial period. The conventional group and combi group showed highest decrease. Interestingly, the reduced energy intake was accompanied with an overall improvement of their dietary quality. This could be the added value of a health professional. They monitor the patient and provide individualized advice and personalized solutions to certain person specific problems. In an mHealth app, such a personalized approach is not possible to such an extent. Furthermore, this interaction with a health professional might be of high importance for long-term maintenance of the results. Future long-term studies should further evaluate the most effective combination of a health professional and an mHealth app.
Most previous studies showed that conventional weight loss programs, as well as mobile weight loss programs, have a positive effect on the level of physical activity [
The amount of sessions in our study might be different compared with other similar studies. In our conventional face-to-face weight loss program, the number of sessions with a dietician was based on the standard of care and the number of sessions that are financially reimbursed through the Belgian social security system. Unfortunately, there is currently no financial reimbursement for the sessions with a physical activity coach in Belgium. Therefore, the content and number of sessions in the conventional face-to-face weight loss program were based on their hypothesized effectiveness from previous research among Belgian adults [
Our study has a few limitations that should be kept in mind. The first limitation of this study is the sample size. Although 102 participants started the trial, some participants dropped out during the trial (n=21). However, when using the data of our combi group, a sample size of 15 would have been required. Furthermore, to see whether the data of these dropouts affected our results, a per-protocol and an ITT analyses was performed, which showed no differences on the main outcomes. A second limitation is the use of the accelerometer on the wrist. The data with regard to physical activity levels in our study were relatively high. Previous studies have already shown that the data from the accelerometer depends on the location of measurement on the body [
In conclusion, our study showed that a conventional weight loss program could partially be completed with an mHealth app without affecting the effectiveness. Such combined approach could support health professionals and reduce their workload. Further ways of combining conventional weight loss programs with mHealth apps should be further explored. Whether such combined programs are also cost-effective should be further investigated. Furthermore, long-term studies should evaluate whether the effects of a combined program can be maintained over a long time period.
CONSORT‐EHEALTH checklist (V 1.6.1).
analysis of variance
body mass index
blood pressure
Food Frequency Questionnaire
high density lipoprotein cholesterol
health enhancing physical activity
International Physical Activity Questionnaire-Short Form
intention-to-treat
metabolic equivalent of tasks
mobile health
moderate to vigorous physical activity
randomized controlled trial
standard deviation
triglycerides
waist circumference
This project is partially funded and realized in collaboration with imec, Belgium. BrandNewHealth developed the weight loss app.
None declared.