Objective: The increasing number of osteoporosis patients is one consequence of our rapidly aging society. More specifically, post-menopausal women experience a marked decrease in bone mass. As the highest possible peak bone mass must be acquired during young adulthood, we evaluated the correlation of the physical characteristics and lifestyle habits with bone mass indexes in Japanese female high school students.

Methods: The speed of sound (SOS) and osteo sono assessment index (OSI) of the talipes calcaneus were measured as bone makers among 16- and 17-year-old female high school students. The students also responded to a questionnaire survey about their characteristics and lifestyles. To evaluate the correlations of various factors with SOS and OSI, a forced-entry multiple regression analysis was conducted. For this, SOS and OSI were used as dependent variables and height, body weight, grip strength, sleep environment, sports club participation, and current ingesting milk as independent variables.

Results: The standard partial regression coefficient revealed significant correlations of SOS with body weight (β=0.150, p<0.05) and, a stronger correlation with sports club participation (β=-0.224, p<0.01). For OSI, the strongest correlation was observed with sports club participation (β=-0.193, p<0.01), followed by body weight (β=0.157, p<0.05) and the sleep environment (β=-0.132, p<0.05). It was shown that exercise club participation had the strongest influence on SOS and OSI.

Conclusion: Sports club participation and body weight were positively correlated with increased bone mass indexes, and it was suggested that participation in exercise club activities was most important for acquiring bone mass.

Purpose: This study examined whether the associations between exercise social support and exercise behavior were different by extraversion.

Methods: In this cross-sectional study, a mailed survey was completed by 78 middle-aged and older married couples (n=158) who were randomly sampled from the residential registries of Chuo Ward in Kobe city, Takasago city, Miki city, and Shiso city. Exercise time was measured with a diary and moderate-to-vigorous walking time and step counts were measured with an accelerometer, and then they were treated as exercise behavior variables. Exercise social support, extraversion, and basic factors (gender, age, educational background, frailty, and employment status) were measured with a questionnaire. Multiple regression analyses were conducted to analyze the data, with exercise behavior variables as the dependent outcomes.

Results: Among all participants, the interaction between exercise social support and extraversion significantly regressed on exercise time (β=0.16, p=0.04), moderate-to-vigorous walking time (β=0.16, p=0.04), and step counts (β=0.16, p=0.03). When the sample was stratified by extraversion, exercise social support significantly regressed on exercise time (β=0.32, p=0.03), moderate-to-vigorous walking time (β=0.28, p=0.03), and step counts (β=0.27, p=0.04) among the high-extraversion group. However, exercise social support did not significantly regress on exercise behavior variables among low- and middle-extraversion groups.

Conclusions: Exercise social support was positively associated with exercise behavior only among highly extraverted people. Exercise social support may have a desirable influence on exercise behavior among extraverted people, but a limited influence on introverted people.

Objectives: We examined the effect of a health class in a junior high school, using teaching materials intended to enhance the perceived "susceptibility" of adverse effects towards nonprescription drugs.

Methods: In this quasi-experimental study, participants were 160 third-year junior high school students, allocated into two groups of 80 students. The first group received a health class using case-based teaching materials, focusing on the perceived "susceptibility" of adverse effects. For the second group, the health class used teaching materials focused on natural healing power. We analyzed the changes of the perceived "susceptibility" of adverse effects, the consciousness of adverse effects, and the self-efficacy of the prevention of adverse effects, one week prior, one week after, and three months after the health class.

Results: In the class using case-based teaching materials that focused on the perceived "susceptibility" of adverse effects, all items regarding perceived "susceptibility," and all items regarding the consciousness of adverse effects became significantly higher (p<0.001). Both items of self-efficacy of the prevention of adverse effects resulted in significant differences. The class using teaching materials that focused on natural healing power resulted in, the same score across all items of the perceived "susceptibility" of adverse effects, but items regarding the consciousness of adverse effects and the self-efficacy of the prevention of adverse effects became significantly lower.

Conclusion: Case-based teaching materials focused on the perceived "susceptibility" of adverse effects, resulted in desirable changes for the perceived "susceptibility" of adverse effects, and the consciousness of adverse effects.

Aims: 1) To describe the background of plans to prolong healthy life expectancy and establish a social environment for health promotion, 2) to quantitatively measure the effect of lifestyle improvement and health promotion on the costs of medical care and long-term care, and 3) to suggest novel strategies for health promotion and disease prevention.

Contents: One of the targets of Health Japan 21 (the second term) is "to extend healthy life expectancy more than the increase of life expectancy". This target is now being achieved, and further development is expected. With regards to the "targets for putting in place a social environment to support and protect health", we examined the annual trends in smoking rate and the comparison of daily number of steps by prefecture as examples. We demonstrated that one's lifestyle is affected by the social environment, and further discuss the strategies to establish such an environment. Moreover, based on our cohort study, we demonstrated that basic lifestyle risk factors, including smoking, obesity, and physical inactivity, contribute to 12.8% of medical care expenditure. Thus, we examined the effects of health promotion and disease prevention strategies on the costs of health and long-term care. Lastly, we introduce processes and effects of strategies implemented in Western countries, including salt intake reduction and fluoridation of public drinking water, as examples of a large paradigm shift in public health, in which interventions have shifted from individual-based strategies to society/community-based strategies.

Conclusion: Health promotion and disease prevention are the only means to simultaneously achieve three goals: 1) improvement of the quality of life among the individuals, 2) stabilization of public finances for social security, and 3) improvement of socioeconomic vitality. As Japan's population decreases and the society ages, expectations for health promotion and disease prevention have been increasing more than ever.

Purpose: Behavioral science is not easy to apply to health promotion as it is challenging to tackle health inequalities only by this. This manuscript introduced ways of using behavioral economics to reduce health inequalities in population health strategies, including the frameworks of "PROGRESS-Plus" and "CAN".

Contents: Socio-economic factors are associated with health inequalities in Japan. Such evidence has been accumulating and it is crucial to use effective health interventions on the inequalities. In a systematic review, "PROGRESS-Plus" was proposed as a framework to identify the social determinants of health and to evaluate the impacts of health interventions. The framework includes representative socio-economic indicators for health inequalities and it will be useful for health intervention studies in Japan. Behavioral economics can be also applied to health promotion as it can increase the effectiveness of population health strategies. As one of such applications of behavioral economics, "CAN" (Convenience, Attractive and Normative) framework has been already used to promote healthy diet.

Conclusion: In addition to classical behavioral science, behavioral economics, has a great potential to promote populations' health and to eliminate health inequalities among the populations in Japan.