Systematic Review Smartphone Apps For Diet And Weight Loss EStore

dimensions; selection bias, study design, confounders, blinding, data collection methods,withdrawals and drop outs, and outcomes (30). Each of these dimensions is rated on a scaleof 1-3, with 1 strong, 2 moderate, 3 weak. Each study was independently checked forquality by two reviewers (the first and second authors). A third reviewer was available toarbitrate should the two reviewers disagree after discussion of the criteria; however this wasnot necessary as the reviewers reached 100% consensus after discussion. Table 2 containsquality ratings for each study.[Insert Table 2 here]Data extractionA standardised data extraction sheet was developed in accordance with recommendations byCochrane (31) for the purpose of the review. This included a thorough and in depth extractionof information in the following areas: general information, study characteristics, samplecharacteristics at baseline, inclusion/exclusion criteria, measures used, intervention details,and analyses and statistical findings. This sheet was developed and then independentlychecked by two authors to agree content prior to data extraction.Data synthesisThe studies retrieved for inclusion were considered for meta-analysis to synthesise the data.Whilst the outcome measures used were similar (weight in kg and BMI) and the time pointswere similar (6 months) the intervention studies were too heterogeneous in their design and inthe elements that made up the intervention (29), therefore making meta-analysis an unsuitablemethod for synthesising the data (32). This review therefore presents a narrative synthesis ofthe study findings.8

RESULTSStudy selection[Insert Figure 1 here]Figure 1 summarises the study selection stages for the review. In total 6070 papers wereidentified from the search process. These include 45 from CINAHL, 7 from Cochrane, 5 fromEBSCO, 213 from Google Scholar, 105 from Ingenta, 894 from JSTOR, 289 fromMEDLINE, 31 from OVID, 1512 from Proquest/ASSIA, 12 from PSYCARTICLES, 115from PSYCINFO, 659 from PUBMED, 149 from science direct, 41 from Sportdiscus, 491from Wiley, 671 from Web of Knowledge. In addition, 831 were identified from handsearches and grey literature searching including; 7 from Obesity Journals, 122 from referencelists of relevant articles, 699 from Mendeley, and 3 from social media. Of the 6070 papers,1380 were duplicates and removed from the searches. After title and abstract review, 4661studies were excluded leaving 29 eligible studies. The last search for the study was conductedon 12th April 2015. After the full texts of the 29 studies were screened in detail using the datainclusion/exclusion sheets 10 percent of these were reviewed independently by the secondauthor and 100% agreement on inclusion/exclusion was reached. (A list of the 29 studies withreasons for inclusion/exclusion can be found in Table S1 in Appendix 1 - supportinginformation). Nine studies were identified as meeting the eligibility criteria. Of these ninepapers, five reported data from the same two studies (three papers reported one study, andtwo papers reported a second study), these were merged leaving six studies for full review.Study characteristicsTable 3 provides a summary of the main characteristics of the six studies included in thereview(33-38), The studies were reviewed and compared on samples who participated, the9

designs of the intervention studies, and the components included in the interventionsincluding application characteristics, practitioner input, and dietary counselling provided.Findings were synthesised on the effect of the interventions on weight loss, and adherence tostudy protocols. Each of these will be reviewed in turn below.[Insert Table 3 here]Research quality and designBased on the McMaster tool (30) ratings, the studies all achieved an overall quality rating of“moderate”. Study design was determined using the Cochrane tool for study design features(39). Four of the studies used a randomized controlled trial design, which is argued to be thegold standard for quantitative intervention study design (40). Of these four studies, only onehad a control (usual care) comparator group (35), the rest of the studies had comparisongroups of other types of self-monitoring weight loss interventions such as website monitoring(34), paper and pencil diaries (34, 37) and use of a smartphone application only without anyother counselling (33). One study (38) used a non-randomized controlled trial design whereparticipants were allocated to the intervention group only if they already owned an IPhone.This could introduce some bias into the findings; however when they compared theintervention group with their paper and pencil group on baseline measures there was nodifference in any of the potential confounders identified. Nonetheless, it needs to be notedthat this lack of difference may be due to lack of power in the study. One study used alongitudinal pre-post design to test the efficacy of a smartphone intervention withparticipants’ scores at baseline acting as control measures.Sample characteristics recruitment and attrition10

There are some similarities in the samples that participated in the interventions. Five of thesix studies were conducted in the United States of America (33, 35-38), and one in the UnitedKingdom (34). All studies recruited overweight or obese adults through a number ofmethods including television and newspaper advertisements, flyers, in routine appointmentsand physician referrals. All studies reported that there were no differences between theircontrol condition group and the intervention group on demographic and anthropometric datasuch as age, gender, BMI, weight, or energy intake at baseline. Participants in all studies hadan average age of between 42 - 44 years old with the exception of one study (36), whoseparticipants’ average age was slightly higher at 53 years. All studies had more femalesparticipating in their studies than males, and all participants had a BMI ranging between25kg/m2 and 50kg/m2 at baseline. Between 42 - 91% of participants in the studies were white,and 5 - 49% of participants were Black. Three studies (33, 36, 37) reported the marital statusof participants with around half of participants reported being married in each study. Threestudies reported educational level (33, 35, 36) and reported that the majority of participantshad some level of college education. There were some variations in attrition from the studiesranging from 10% to 36%; however all studies concluded that they had non-problematic ratesof drop out. Only two studies fully reported conducting a power analysis to determineappropriate sample size for detecting differences (35, 37).Smartphone Application characteristicsFour studies used pre-existing smartphone applications currently available via either androidor IPhone stores (33, 35, 37, 38) two studies (33, 38) used the LoseIt! application, whereasone (35) used the MyFitnessPal application, and one (37) used the Fat Secret Calorie Counterapplication. Two studies (34, 36) developed their own smartphone application based onweight loss programs specifically for the study. The two smartphone applications that weredeveloped were similar in their functionality to the pre-existing applications and contained11

goal setting, self-monitoring and feedback functions. All studies reported that training in howto use the applications was provided. This varied in how participants were trained; twostudies (34, 36) provided links to self-help videos that described the features of theapplication and demonstrated how it worked, the other studies (33, 35, 37, 38) trained theparticipants in how to use the application at the time that baseline measures were taken.All applications used in the studies were primarily used as a self-monitoring tool whereparticipants could voluntarily log their dietary intake on a daily basis. Each application had adatabase of foods along with nutritional content. In addition, the applications made use of thebar code scan function of the smartphone to help the user to log their food intake. Allapplications also had a function where participants could log physical activity. Theapplications provided feedback on progress in terms of calorie intake against calorie goals.This feedback was typically provided in graphical format; either pie charts or bar charts. Twoof the studies provided extra feedback (34, 36) in the form of tailored text messages toparticipants. However, the content and timing of these messages differed between the twostudies. One study (34) sent weekly motivational messages that encouraged self-efficacy forweight loss and rehearsal of weight loss goals. These were automatic messages that weretriggered at specific points in progress towards weight loss goals. Whereas another study (36)sent messages one to three times per week that were tailored to the specific participant’scurrent weight loss and caloric intake. What determined the frequency of delivery of textmessages was not reported. These messages gave tips and advice on diet and exercise.Applications used in all of the studies had a goal setting function where a weight loss orcalorific intake goal could be inputted for comparison with progress. In two studies (34, 36),the goals that were set were determined by the participant. In one study (36), this was set to alimit of between 0.23 and 0.9 kg per week weight loss whereas limits are not reported in theother study (34). In three of the studies the researchers set the weight loss goals for the12

participant. Typically this was the same goal for all participants in all conditions of the study.One study (38) set the weight loss goal at 0.45 kg per week, whereas (36) set the goal atbetween 0.45 and 0.9 kg per week with an aim to lose 10% of body weight over the sixmonth study. One study (33) specified that participants were aiming to lose 5% of weight bythe end of six months and increase physical activity to 150 minutes per week.In the two studies that created their own weight loss application (34, 36), there was no reportof any social support or social media functions available to participants. However, there wasa social media function available in pre-existing smartphone applications. Two of the studiesthat used the pre-existing applications (35, 37) actively encouraged the use of social mediafunctions, with one study using the social media function to encourage contact with the studycounsellors. The other study that used an application with social media function did notreport how much their participants engaged with this aspect of the application, or whetherthis was encouraged even though it was available (33).Practitioner involvement and dietary counsellingTwo of the studies (33, 36) had more regular face to face contact with participants than just atmeasurement time points of baseline, three and six months. One study (36) had weekly weighin sessions where behavioral targets and behavioral prompts were created and programmedinto the application so that they could be delivered at an appropriate time. In the other study(33), participants had varying degrees of contact with researchers depending on whichcondition the participants were allocated to. In the intensive counselling group participantshad weekly contact with nutrition counsellors in the first month then every two weeks for theremainder of the trial. In the less intensive counselling group, participants had contact withnutrition counsellors every fortnight for the first month then monthly for the remainder of thetrial. Participants in the smartphone condition had only one session of basic nutritional13

counselling at the start of the trial. In one study (38) participants who were not in thesmartphone application group were given a personalised nutritional plan, and were sentweekly emails to encourage healthy eating.In contrast, two studies (36, 37) provided electronic means of nutritional counselling.Participants in one study (37) could regularly download podcasts that encouraged healthyeating along with emphasising the importance of self-monitoring of diet and exercise.Whereas in the other study (36), participants were provided with video weight loss lessonscomprising information on the importance of planning meals, self-monitoring of diet, andmotivational information. In (35), participants were given a one page educational leaflet onhealthy eating and dietary advice at three months.Weight loss across time[Insert Table 4 here]As Table 4 shows, three studies found a statistically significant difference in weight lossacross time in all comparator groups (34, 37, 38). Two of these studies (34, 37) reported thatthe majority of participants had lost clinically significant amounts of weight across the sixmonths of the trials. One study (36) reported the greatest amount of weight loss in thesmartphone application condition. Two studies (33, 36) reported no significant change inbody weight across time though both studies report participants as having lost weight acrossall conditions. It needs to be noted here that both of these studies report insufficient powertherefore their findings need to be interpreted with caution. One study (35) reported that therewas no significant difference in weight across time in their intervention group and the usualcare group actually increased their weight over the duration of the study.Weight loss differences between groups14

Four of the six studies (33, 35, 37, 38) reported that there was no significant differencebetween comparison groups in the amount of weight lost over the six month period. The onlyother study that compared different groups of participants (34) found that those participantswho were assigned to the smartphone application condition lost significantly more weightthan those allocated to a website logging condition, but there was no significant difference inweight loss between those in a paper diary group and smartphone application group.Dietary intake changesTwo studies (33, 37) examined dietary intake in addition to weight and BMI. One (37) alsoexamined energy intake and found that participants in the podcast plus smartphoneapplication group consumed significantly less calories and fat at six months than the podcastplus paper diary group. Two (35, 38) found no significant difference between groups on selfreported dietary behaviors. One (38) reported no difference in healthy eating indices acrossthe study, or between groups. Neither (34) nor (36) reported examining dietary behavior intheir study.Adherence to study protocolsIn three studies (34, 35, 38), there was a significant difference in drop out across thecomparison groups. On the whole, participants were less likely to drop out from thesmartphone application groups, than groups that have other methods of self-monitoring suchas a paper diary. In all of the studies that compared different groups of participants, thenumber of days over the trial period that participants engaged in smartphone self-monitoringof diet was higher than other monitoring methods. However, one study (35) reported asignificant decrease in the number of logins to the application in the final month of the studywith some participants reporting recording of intake as tedious, and that they were toostressed or too busy.15

DISCUSSIONThe purpose of this review was to systematically explore the research examining theeffectiveness of smartphone applications that use self-regulatory strategies for weight loss inoverweight and obese adults. The authors rigorously reviewed six studies that met theinclusion criteria of using dietary self-regulatory strategies in a smartphone application forweight loss in overweight or obese adults in one or more conditions of the study.Overall, the findings suggest that smartphone applications for dietary self-monitoring areeffective at encouraging weight loss. All of the studies reported that participants who usedsmartphone applications for dietary tracking lost some weight over the duration of the study.Three studies reported that this was a significant amount of weight lost over time, and twostudies reported that the weight lost was clinically significant at between 5-10% of bodyweight lost over the duration of the intervention. The studies also reported that participantswere more likely to remain adherent to self-monitoring protocols if they were using asmartphone application for tracking dietary intake. These findings are encouraging assmartphone applications could be a useful additional tool to support overweight or obeseindividuals with weight loss.Nonetheless, four studies reported that there were no significant differences in weight lossbetween all comparison groups meaning that participants in all groups were losing similaramounts of body weight by self-monitoring their dietary intake. It should however be notedthough that the majority of the studies did not employ a non-intervention comparator group intheir design. This means that the participants in other comparison groups were receivingsome level of self-regulatory weight loss intervention making the actual scale of the efficacyof smartphone applications difficult to discern. As a result it is difficult to conclude thatsmartphone applications are any more effective for weight loss than other monitoring16

methods. However, whilst not significant, there was a trend for participants in the smartphoneapplication groups to lose slightly more weight than other groups - even when compared to ausual care group. Future studies should ensure that there is a usual care or no interventioncondition in addition to other monitoring methods to determine whether smartphoneapplications are a useful tool to support or aid weight loss.The design of the studies can also be called into question as some of the studies did notprovide comparable treatments and controls to all conditions meaning that other extraneousinfluences may have affected the findings. For example, one study (38) offered nutritionalcounselling and diet planning to the comparison groups but not to the smartphone applicationgroup. This might have obfusca

A number of studies have developed new weight loss applications, and some have evaluated existing weight loss applications that incorporate dietary self-regulatory strategies. Therefore it would be useful to summarise the evidence to date on how effective these smartphone applications are for weight loss.