The relationship between bone mineral content (BMC) divided by bone width (BW) and diet and lifestyle in early adulthood were investigated from the view point of preventing osteoporosis at a young age in Asian women. BMC/BW of 161 healthy Asian women aged 19-25 y were measured by single-photon absorptiometry. Current and past dietary habit's and physical activity were also studied. BMC/BW varied from 0.21 to 0.48 g/cm2. Bone density correlated well with dietary habit from infancy to the present especially with calcium and past physical activity. These two factors showed additive effects on BMC/BW. In multiple-regression analysis, liking sports, body mass index, no milk intake in childhood, protein intake, frequency of dieting, and skipping meals were contributors to bone density and predictive of 23% of the variability in BMC/BW in the total group. The multiple-regression coefficient was 0.518. Smoking, drinking, and duration of sunbathing might have no effect on BMC/BW in early adulthood.