JMIR Publications

ABSTRACT

Background:

Web-based multiple health behavior change (MHBC) interventions have proved to be effective in promoting physical activity (PA) and increasing fruit-vegetable consumption (FVC) among Chinese college students. However, limited research has examined the intervention effects of web-based MHBC interventions on a combined healthy lifestyle (i.e., adhering to both PA and FVC behavioral recommendations) among college students. In addition, the salient psychosocial mediators of successful MHBC need to be addressed.

Objective:

This study aimed to examine the effectiveness of an 8-week web-based MHBC intervention on promoting a combined healthy lifestyle and increasing psychosocial determinants of behavioral change (i.e., intention, self-efficacy, planning, and social support all relating to PA and FVC). Further, the study aimed to identify whether changes in these psychosocial determinants of PA and FVC could mediate the intervention effectiveness on the combined lifestyle indicator.

Methods:

This study was a secondary analysis for a three-arm, double-blinded randomized controlled trial. A total of 552 Chinese college students were randomly assigned to one of three groups, including a PA-first group (4-week intervention on PA followed by 4-week on FVC), an FVC-first group (4-week intervention on FVC followed by 4-week on PA), and a control group (8-week placebo treatment irrelevant to PA or FVC). The intervention content for PA-first and FVC-first groups was designed based on the health action process approach (HAPA) model. Data for analyses was collected at baseline (T0), post-intervention test (T1; 8 weeks after T0), and follow-up test (T2; 12 weeks after T0).

Results:

At baseline, only 13.9% of participants adopted a combined healthy lifestyle. After 8 weeks, the percentage of participants with a combined healthy lifestyle increased prominently (36.2%). Participants in the PA-first and FVC-first groups were respectively 3.24 and 5 times more likely to adopt a healthy lifestyle compared to the control group at T1. After 12 weeks, a total of 35.5% of participants maintained the combined healthy lifestyle. Participants who received the web-based MHBC interventions were 2.99 (PA-first) and 4.07 (FVC-first) more likely to maintain a combined healthy lifestyle relative to the control condition at T2. Intervention effects favored both intervention groups in self-efficacy and planning for PA and in intention and planning for FVC compared to the control condition. For mediation analyses, changes in self-efficacy for PA, and intention for FVC significantly mediated the intervention effectiveness on the immediate lifestyle change after 8 weeks (T1). Changes in intention for FVC was identified as a significant mediator for facilitating sustained lifestyle change after 12 weeks (T2) among Chinese college students.

Conclusions:

This study provides empirical evidence for the effectiveness of an 8-week theory-based and web-based MHBC intervention program on promoting a combined healthy lifestyle and several psychosocial determinants of behavioral change among Chinese college students. These research findings also add new evidence to the underlying psychosocial mechanisms of successful MHBC. Overall, this study may have considerable implications for future web-based MHBC research and practice. Clinical Trial: N/A.