To our knowledge, there have been no previously published studies examining the effectiveness of this TECH (BodyMedia Fit) when used alone or in combination with an in-person behavioral weight loss intervention in overweight and obese adults. The program was successful in producing weight loss in all treatment groups at 6 months and a trend indicated a greater weight loss for those using the technology and attending regular in-person meetings than those in the standard program. Using an earlier version of this technology system, Polzien et al
) reported that a combination of the armband technology and face-to-face intervention produced a 2.1 kg greater weight loss at 3 months than the standard program. After 6 months, the present study demonstrated that the combination of technology and face-to-face intervention resulted in weight losses 1.7 and 5.1 kg greater than the standard group based on completers and ITT analyses, respectively. Although the current investigation included a longer, more intensive in-person behavioral program than the previous study, the results are consistent in suggesting that the TECH may produce an additive effect on weight loss, equivalent to ~2 kg, when combined with an in-person behavioral weight loss intervention.
It is interesting that the weight loss in the TECH group was 5.8 kg based on ITT, and 7.6 kg based on objectively measured weight for individuals completing the study. These weight losses were comparable or exceeded the weight loss observed in SBWL based on ITT (3.7 kg) or completer analyses (7.1 kg). Although these results need replication, they may provide some evidence that a technology-based program such as the BodyMedia Fit system, when coupled with a brief monthly intervention telephone call, can result in weight loss that approaches the magnitude of weight loss observed in standard face-to-face weight loss intervention programs for a period of 6 months. However, direct comparison between TECH and SBWL based on this study must be interpreted with caution as the SBWL intervention resulted in less weight loss than is typically observed in these types of interventions within 6 months (6
). Moreover, attrition in SBWL was higher than what is typically observed and reported in the literature (6
). While speculative, the lower weight loss observed in SBWL in this study may have been a result of subjects expecting to receive the technology as a component of their intervention due to the eligibility criteria requiring that subjects have access to the internet and be willing to use technology as a component of the intervention. Thus, results of the present study require replication, with future studies closely examining how preference for technology within the context of an intervention affects compliance and retention of participants.
The present study, and in particular, SBWL, resulted in slightly lower retention rates and weight losses after 6 months compared to SBWL programs which generally produce weight losses of ~10% with participant retention near 80% (6
). Attrition significantly differed between treatment groups with the highest participant loss detected among the standard group (47%). Despite differences in magnitude and intervention design and length, the trend for the technology to enhance participant retention is consistent with findings by Polzien et al
). However, caution should be used when interpreting these results. Due to the poor performance of SBWL, a fair comparison between groups may not be possible. As mentioned previously, we speculate that the high attrition and poor weight loss outcomes in the standard group were a result of not receiving the enhanced program that included the technology system, which may have been preferred by some of the standard group subjects. Future studies should consider assessing group preference at baseline to examine any influence on outcomes.
Regardless of group assignment, significant improvements in cardiorespiratory fitness and reductions in waist and hip circumference, and percent body fat were observed. Furthermore, the current study produced increases in physical activity similar to previous in-person behavioral programs (23
) and higher than previous Internet-based programs (12
) at 6 months. Although not significant, the technology users demonstrated the greatest increases in physical activity, which is similar to the trends observed by Polzien et al
). In addition, the lack of differences observed between groups (for weight loss, body composition, and fitness) suggest that the use of the technology system, independent of a face-to-face program but combined with an introductory weight loss session, weekly behavioral mailings, and monthly telephone calls, may have the ability to produce outcomes similar to those seen in standard in-person behavioral weight loss programs.
Across all treatment groups, the intervention produced a reduction in dietary intake from baseline to 6 months which is consistent with previous Internet (12
), technology-based (11
), and in-person behavioral (21
) programs. Eating behaviors significantly improved at 6 months, with the greatest improvements observed among the combined program. Similarly, those using the technology system and attending in-person sessions self-monitored dietary intake with the greatest frequency. The website used with this technology system included a searchable food database that automatically calculates dietary information such as caloric intake and fat which may make self-monitoring less burdensome than the paper and pencil method. In addition, by regularly self-monitoring dietary intake and uploading energy expenditure information from the armband, individuals using the website could receive feedback on overall calorie balance, which may be beneficial to those trying to lose weight. Polzien et al
) did not observe any differences among self-monitoring behaviors between the technology or standard groups. However, more recently, Harvey-Berino et al
) observed a trend among an Internet only and Internet plus in-person weight loss group to complete a higher proportion of self-monitoring journals than an in-person program, which suggests that the Internet may facilitate adherence. In the present study, among all groups, higher frequency of self-monitoring dietary intake was significantly related to greater weight losses at 6 months. Consistent with previous reports (6
), self-monitoring dietary intake is an essential and effective component to weight loss programs, and the technology used in this study may provide an effective technique to traditional diaries to self-monitor key weight loss behaviors.
Participants in the current study were instructed to wear the armband during waking hours and to remove it during any water activities (bathing, showering, and swimming). Throughout the 6-month intervention, the armbands were worn for an average of 16.7 h/day, with a compliance rate between 81–96%. Previous research using the earlier version of the armband indicated the monitor was worn for ~9–10 h/day (11
). The present study may have observed higher rates of on-body time due to the smaller and more comfortable design. The high compliance may suggest that the armband energy monitor was widely accepted by participants.
Although there have been no previously published studies reporting the effectiveness of the BodyMedia Fit system, these findings should be interpreted with caution as a result of several limitations. The sample size for this pilot study was relatively small (17 subjects/group), which may have resulted in insufficient Statistical power to detect significant differences between the intervention groups. Poor retention rates and weight loss outcomes in SBWL may limit the ability to make meaningful comparisons between this condition and both TECH and SBWL+TECH. There was low representation of minorities and males, which limits the ability to conduct secondary analyses for ethnic/racial or gender comparisons. Although the present study was longer than the 12 week program reported by Polzien et al
), there is limited ability to infer the effectiveness of the technology-based components of the intervention beyond 6 months. The design of this study did not allow us to distinguish which components of the technology-based intervention were the most effective for promoting behavior change and weight loss, and future studies may need to be designed to specifically examine each of these technology components (e.g., armband, food tracking, etc.).
In conclusion, the current investigation was successful in producing weight loss, increasing physical activity, and decreasing dietary intake. Furthermore, the results support the use of a technology-based system, combined with monthly telephone calls to produce weight loss that approaches the magnitude of weight loss and adoption of eating and physical activity behaviors that is typically observed in standard in-person behavioral weight loss interventions. Thus, the commercially available technology used in this study appears to be effective for weight loss, reducing energy intake, and increasing physical activity in the absence of in-person intervention contact. This investigation served as a pilot study, thus, additional studies should be completed to further examine and replicate the results observed on the effects of the use of this technology system, when used alone or combined with an in-person behavioral weight loss intervention. In addition, future studies should examine the use of this system for a longer period of time, to determine whether these findings are sustainable past 6 months. If shown to be effective in future studies, this technology may provide an alternative to in-person lifestyle behavioral intervention for weight loss.