Changes in body weight, awareness, and behaviors among workers participating in an online specific health guidance program incorporating multiple nudges: a process evaluation

Objectives: In Japan, specific health guidance (SHG) — comprising intensive and motivational support — has increasingly incorporated nudges and online modalities to prevent metabolic syndrome. This practice aimed to conduct a process evaluation of an online SHG program that integrated multiple nudges by examining changes in body weight, health awareness, and health-related behaviors. Methods: A 100-day online SHG program was conducted within a health insurance association of a Japanese securities firm. The program included three group seminars, individual counseling, self-monitoring via a mobile application, and distribution of video content. In addition to health education, multiple nudges (eg, implementation intention and commitment nudges) were embedded throughout the program. Results: The analysis included 181 respondents (94 intensive; 87 motivational) who completed follow-up surveys. Improvements were observed across most outcomes; for example, 51.4% of participants experienced weight reduction (56.4% in the intensive group and 46.0% in the motivational group). Notably, the proportion of participants engaging in self-weighing more than once per week increased substantially, from 39.4% to 83.0% in intensive support group (Cohen’s h=0.93), and from 49.4% to 77.0% in motivational support group (Cohen’s h=0.58). Conclusions: The combination of multiple nudges and health education can have promoted engagement in healthy behaviors. This practice has limitations such as not assessing long-term outcomes. To overcome them, a longitudinal study using multi-year health checkup data is planned.