We studied the relationships between weight variables and spine bone mineral density (BMD) in 183 postmenopausal women aged 34-76 years. There was a significant positive correlation of current body mass index (cBMI) and % of ideal body weight (IBW) with BMD. Moreover, the increase in BMI and % IBW was also positively and significantly associated with a higher age-adjusted lumbar BMD. Weight gain, estimated as the difference between current body weight and past "ideal" body weight, was associated with significant age-adjusted BMD with a threshold of 17%, and postmenopausal women with a gain of over 17% had significantly higher spine BMD.