Effect and factors associated with weight and waist circumference reductions in information and communication technology-based specific health guidance.

Objectives: Specific health guidance (SHG) has served as a preventive intervention for metabolic syndrome in Japan since 2008. For SHG, health professionals guide diet and physical activity to achieve body weight (BW) and waist circumference (WC) reductions. Since 2013, SHG intervention using information and communication technology (ICT-based SHG) has also been available. Therefore, in this study, we examined the effects of ICT-based SHG, and identified factors associated with BW and WC reductions in response to this intervention. Methods: Our intervention was performed using a smartphone application with videophone guidance and message exchanges provided by health professionals. We analysed 1,994 participants. Primary outcomes included changes in BW and WC after versus before the intervention. We used multiple linear regression analyses to identify factors associated with reductions in BW and WC due to the intervention. Results: The mean ages were 49.3 (standard deviation [SD], 5.8) years for males and 50.5 (SD, 5.8) years for females. The mean BW change was -1.37 kg for both sexes. The mean WC changes were -1.05 for males and -2.05 cm for females. For males, baseline body mass index, pre-intervention action history, and the numbers of videophone communications and messages were significantly associated with larger changes in BW and WC. For females, no factors were significant for BW reduction, while baseline WC and pre-intervention action history were associated with WC reduction. Conclusions: ICT-based SHG reduces BW and WC. Videophone communication and messaging are associated with reductions in BW and WC in males. These results may help to improve the efficacy of ICT-based SHG.