Personality and body mass index: a cross-sectional analysis from the Miyagi Cohort Study

Obesity is an increasingly prevalent public health problem worldwide, and is associated with a higher risk of developing various noncommunicable diseases. To further examine the association between personality and overweight, obesity, or underweight, we conducted a cross-sectional analysis in Japan. We hypothesized that extraversion and psychoticism would have a positive association with overweight, and that neuroticism and lie would have an inverse association with overweight, whereas the association between personality and underweight would be the reverse image of overweight.

In 1990, 30,722 subjects (40-64 years of age) completed a self-administered questionnaire including body weight and height and the Japanese version of the Eysenck Personality Questionnaire-Revised Short Form. Multivariate logistic regression analysis was used to calculate odds ratios for overweight [body mass index (BMI)> or =25.0 kg/m2] or underweight (BMI<18.5) relative to each category on the personality subscale.

In men and women, extraversion and psychoticism had positive associations with overweight, whereas neuroticism had an inverse association. Lie had an inverse association with overweight in men. In men and women, only extraversion had an inverse association with underweight and neuroticism had a positive association with underweight.

Our findings indicate that personality is associated with both overweight and underweight. These results may provide clues to devising more effective measures for preventing overweight, obesity, or underweight or for weight control intervention.