Ishikawa S, et al. - Authors gauged comprehensively, the risk factors for underweight in cross-sectional study in the general population of Japan. They distributed a postal survey in the form of a self-administered questionnaire, and 6084 individuals were entered into the final statistical analysis. The number of teeth were independently correlated with an underweight status, thereby indicating that fewer teeth can increase the risk of being underweight. They noted an independent association of number of teeth, age, alcohol consumption, hypertension, spousal status, smoking habit, appetite, body weight at 20 years of age, habit of going out and physical activity with an underweight status compared with the normal weight group.