[Analysis of processes of elevating calcaneum bone stiffness in young women--from the view point of their life-style].

Calcaneum bone stiffness in 222 young women was investigated by using an ultra-sound bone densitometer (Achilles). Their exercise experiences, amounts of dairy products (including foods which contain a lot of calcium) consumed and 24 questions on their eating attitudes were also analysed. Stiffness showed a significant (p < 0.05) positive correlation with age, BMI and the onset of menarche by polynomial (2) regressions. Using these three variables, expected stiffness was calculated by multiple regression, and according to the differences between the real and expected stiffness, the subjects were divided into three subgroups. Group H which showed higher stiffness, showed significantly (p < 0.05) higher exercise experiences and had the habit of consuming more dairy products and small fish than the other two groups. In all of the subjects, the most important variable which increased the stiffness was the exercise experience at junior high school and the next was the habit of eating small fish. The subjects who customarily ate their meals with their families were more likely to eat small fish. These findings suggest that family eating habits should be noticed not only in post-menopausal women, but also in young girls.