Background and objectives: Each of the effects of physical activity and dietary intake on health is well known, but combined associations of physical activity and dietary intake on health has not been reported yet. Physical activity and dietary intake are key factors for maintaining health of survivors of the Great East Japan Earthquake in 2011. This study aimed to examine combined associations of physical activity and dietary intake with survivors' health status.
Methods and study design: We used data from 6668 participants of a cross-sectional survey taken 3 years (2013) after the disaster. To evaluate combined associations of physical activity and dietary intake, answers to questions regarding these two variables were categorized into four groups: poor physical activity and poor dietary intake (Group 1), poor physical activity and good dietary intake (Group 2), good physical activity and poor dietary intake (Group 3), and good physical activity and good dietary intake (Group 4). Multiple logistic regression analyses were performed by sex, with good self-rated health and good mental health as dependent variables, and age, place of residence, living conditions and physical activity/dietary intake group (with Group 1 as the reference category) as independent variables.
Results: Good self-rated health was associated with age in both sexes, and Groups 3 (male: odds ratios (ORs) 1.84 (95% confidence intervals (95% CIs) 1.32-2.57), female: OR 1.82 (95% CI 1.32-2.51)) and 4 (male: OR 1.96 (95% CI 1.39-2.76), female: OR 1.94 (95% CI 1.42-2.64)). Good mental health was associated with Groups 3 (OR 1.48 (95% CI 1.10-1.97)) and 4 (OR 1.86 (95% CI 1.37-1.97)) for male respondents; and living place (other than temporary housing) (OR 1.45 (95% CI 1.26-1.68)) was associated with Group 4 (OR 1.42 (95% CI 1.09-1.85)) for female respondents.
Conclusions: Good physical activity alone or combined with good dietary intake was associated with good self-rated health and good mental health. Further interventions regarding physical activity and dietary intake are needed to improve the health status of survivors.